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linux-stable/arch/x86/kernel/cpu/feat_ctl.c

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x86/intel: Initialize IA32_FEAT_CTL MSR at boot Opportunistically initialize IA32_FEAT_CTL to enable VMX when the MSR is left unlocked by BIOS. Configuring feature control at boot time paves the way for similar enabling of other features, e.g. Software Guard Extensions (SGX). Temporarily leave equivalent KVM code in place in order to avoid introducing a regression on Centaur and Zhaoxin CPUs, e.g. removing KVM's code would leave the MSR unlocked on those CPUs and would break existing functionality if people are loading kvm_intel on Centaur and/or Zhaoxin. Defer enablement of the boot-time configuration on Centaur and Zhaoxin to future patches to aid bisection. Note, Local Machine Check Exceptions (LMCE) are also supported by the kernel and enabled via feature control, but the kernel currently uses LMCE if and only if the feature is explicitly enabled by BIOS. Keep the current behavior to avoid introducing bugs, future patches can opt in to opportunistic enabling if it's deemed desirable to do so. Always lock IA32_FEAT_CTL if it exists, even if the CPU doesn't support VMX, so that other existing and future kernel code that queries the MSR can assume it's locked. Start from a clean slate when constructing the value to write to IA32_FEAT_CTL, i.e. ignore whatever value BIOS left in the MSR so as not to enable random features or fault on the WRMSR. Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-5-sean.j.christopherson@intel.com
2019-12-21 04:44:58 +00:00
// SPDX-License-Identifier: GPL-2.0
#include <linux/tboot.h>
x86/cpu: Include the header of init_ia32_feat_ctl()'s prototype Include the header containing the prototype of init_ia32_feat_ctl(), solving the following warning: $ make W=1 arch/x86/kernel/cpu/feat_ctl.o arch/x86/kernel/cpu/feat_ctl.c:112:6: warning: no previous prototype for ‘init_ia32_feat_ctl’ [-Wmissing-prototypes] 112 | void init_ia32_feat_ctl(struct cpuinfo_x86 *c) This warning appeared after commit 5d5103595e9e5 ("x86/cpu: Reinitialize IA32_FEAT_CTL MSR on BSP during wakeup") had moved the function init_ia32_feat_ctl()'s prototype from arch/x86/kernel/cpu/cpu.h to arch/x86/include/asm/cpu.h. Note that, before the commit mentioned above, the header include "cpu.h" (arch/x86/kernel/cpu/cpu.h) was added by commit 0e79ad863df43 ("x86/cpu: Fix a -Wmissing-prototypes warning for init_ia32_feat_ctl()") solely to fix init_ia32_feat_ctl()'s missing prototype. So, the header include "cpu.h" is no longer necessary. [ bp: Massage commit message. ] Fixes: 5d5103595e9e5 ("x86/cpu: Reinitialize IA32_FEAT_CTL MSR on BSP during wakeup") Signed-off-by: Luciano Leão <lucianorsleao@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Nícolas F. R. A. Prado <n@nfraprado.net> Link: https://lore.kernel.org/r/20220922200053.1357470-1-lucianorsleao@gmail.com
2022-09-22 20:00:54 +00:00
#include <asm/cpu.h>
x86/intel: Initialize IA32_FEAT_CTL MSR at boot Opportunistically initialize IA32_FEAT_CTL to enable VMX when the MSR is left unlocked by BIOS. Configuring feature control at boot time paves the way for similar enabling of other features, e.g. Software Guard Extensions (SGX). Temporarily leave equivalent KVM code in place in order to avoid introducing a regression on Centaur and Zhaoxin CPUs, e.g. removing KVM's code would leave the MSR unlocked on those CPUs and would break existing functionality if people are loading kvm_intel on Centaur and/or Zhaoxin. Defer enablement of the boot-time configuration on Centaur and Zhaoxin to future patches to aid bisection. Note, Local Machine Check Exceptions (LMCE) are also supported by the kernel and enabled via feature control, but the kernel currently uses LMCE if and only if the feature is explicitly enabled by BIOS. Keep the current behavior to avoid introducing bugs, future patches can opt in to opportunistic enabling if it's deemed desirable to do so. Always lock IA32_FEAT_CTL if it exists, even if the CPU doesn't support VMX, so that other existing and future kernel code that queries the MSR can assume it's locked. Start from a clean slate when constructing the value to write to IA32_FEAT_CTL, i.e. ignore whatever value BIOS left in the MSR so as not to enable random features or fault on the WRMSR. Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-5-sean.j.christopherson@intel.com
2019-12-21 04:44:58 +00:00
#include <asm/cpufeature.h>
#include <asm/msr-index.h>
#include <asm/processor.h>
x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs Add an entry in struct cpuinfo_x86 to track VMX capabilities and fill the capabilities during IA32_FEAT_CTL MSR initialization. Make the VMX capabilities dependent on IA32_FEAT_CTL and X86_FEATURE_NAMES so as to avoid unnecessary overhead on CPUs that can't possibly support VMX, or when /proc/cpuinfo is not available. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-11-sean.j.christopherson@intel.com
2019-12-21 04:45:04 +00:00
#include <asm/vmx.h>
x86/intel: Initialize IA32_FEAT_CTL MSR at boot Opportunistically initialize IA32_FEAT_CTL to enable VMX when the MSR is left unlocked by BIOS. Configuring feature control at boot time paves the way for similar enabling of other features, e.g. Software Guard Extensions (SGX). Temporarily leave equivalent KVM code in place in order to avoid introducing a regression on Centaur and Zhaoxin CPUs, e.g. removing KVM's code would leave the MSR unlocked on those CPUs and would break existing functionality if people are loading kvm_intel on Centaur and/or Zhaoxin. Defer enablement of the boot-time configuration on Centaur and Zhaoxin to future patches to aid bisection. Note, Local Machine Check Exceptions (LMCE) are also supported by the kernel and enabled via feature control, but the kernel currently uses LMCE if and only if the feature is explicitly enabled by BIOS. Keep the current behavior to avoid introducing bugs, future patches can opt in to opportunistic enabling if it's deemed desirable to do so. Always lock IA32_FEAT_CTL if it exists, even if the CPU doesn't support VMX, so that other existing and future kernel code that queries the MSR can assume it's locked. Start from a clean slate when constructing the value to write to IA32_FEAT_CTL, i.e. ignore whatever value BIOS left in the MSR so as not to enable random features or fault on the WRMSR. Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-5-sean.j.christopherson@intel.com
2019-12-21 04:44:58 +00:00
x86/cpu: Clear VMX feature flag if VMX is not fully enabled Now that IA32_FEAT_CTL is always configured and locked for CPUs that are known to support VMX[*], clear the VMX capability flag if the MSR is unsupported or BIOS disabled VMX, i.e. locked IA32_FEAT_CTL and didn't set the appropriate VMX enable bit. [*] Because init_ia32_feat_ctl() is called from vendors ->c_init(), it's still possible for IA32_FEAT_CTL to be left unlocked when VMX is supported by the CPU. This is not fatal, and will be addressed in a future patch. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-9-sean.j.christopherson@intel.com
2019-12-21 04:45:02 +00:00
#undef pr_fmt
#define pr_fmt(fmt) "x86/cpu: " fmt
x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs Add an entry in struct cpuinfo_x86 to track VMX capabilities and fill the capabilities during IA32_FEAT_CTL MSR initialization. Make the VMX capabilities dependent on IA32_FEAT_CTL and X86_FEATURE_NAMES so as to avoid unnecessary overhead on CPUs that can't possibly support VMX, or when /proc/cpuinfo is not available. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-11-sean.j.christopherson@intel.com
2019-12-21 04:45:04 +00:00
#ifdef CONFIG_X86_VMX_FEATURE_NAMES
enum vmx_feature_leafs {
MISC_FEATURES = 0,
PRIMARY_CTLS,
SECONDARY_CTLS,
x86/cpu: Add new VMX feature, Tertiary VM-Execution control A new 64-bit control field "tertiary processor-based VM-execution controls", is defined [1]. It's controlled by bit 17 of the primary processor-based VM-execution controls. Different from its brother VM-execution fields, this tertiary VM- execution controls field is 64 bit. So it occupies 2 vmx_feature_leafs, TERTIARY_CTLS_LOW and TERTIARY_CTLS_HIGH. Its companion VMX capability reporting MSR,MSR_IA32_VMX_PROCBASED_CTLS3 (0x492), is also semantically different from its brothers, whose 64 bits consist of all allow-1, rather than 32-bit allow-0 and 32-bit allow-1 [1][2]. Therefore, its init_vmx_capabilities() is a little different from others. [1] ISE 6.2 "VMCS Changes" https://www.intel.com/content/www/us/en/develop/download/intel-architecture-instruction-set-extensions-programming-reference.html [2] SDM Vol3. Appendix A.3 Reviewed-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Robert Hoo <robert.hu@linux.intel.com> Signed-off-by: Zeng Guang <guang.zeng@intel.com> Message-Id: <20220419153240.11549-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-19 15:32:40 +00:00
TERTIARY_CTLS_LOW,
TERTIARY_CTLS_HIGH,
x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs Add an entry in struct cpuinfo_x86 to track VMX capabilities and fill the capabilities during IA32_FEAT_CTL MSR initialization. Make the VMX capabilities dependent on IA32_FEAT_CTL and X86_FEATURE_NAMES so as to avoid unnecessary overhead on CPUs that can't possibly support VMX, or when /proc/cpuinfo is not available. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-11-sean.j.christopherson@intel.com
2019-12-21 04:45:04 +00:00
NR_VMX_FEATURE_WORDS,
};
#define VMX_F(x) BIT(VMX_FEATURE_##x & 0x1f)
static void init_vmx_capabilities(struct cpuinfo_x86 *c)
{
x86/cpu: Add new VMX feature, Tertiary VM-Execution control A new 64-bit control field "tertiary processor-based VM-execution controls", is defined [1]. It's controlled by bit 17 of the primary processor-based VM-execution controls. Different from its brother VM-execution fields, this tertiary VM- execution controls field is 64 bit. So it occupies 2 vmx_feature_leafs, TERTIARY_CTLS_LOW and TERTIARY_CTLS_HIGH. Its companion VMX capability reporting MSR,MSR_IA32_VMX_PROCBASED_CTLS3 (0x492), is also semantically different from its brothers, whose 64 bits consist of all allow-1, rather than 32-bit allow-0 and 32-bit allow-1 [1][2]. Therefore, its init_vmx_capabilities() is a little different from others. [1] ISE 6.2 "VMCS Changes" https://www.intel.com/content/www/us/en/develop/download/intel-architecture-instruction-set-extensions-programming-reference.html [2] SDM Vol3. Appendix A.3 Reviewed-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Robert Hoo <robert.hu@linux.intel.com> Signed-off-by: Zeng Guang <guang.zeng@intel.com> Message-Id: <20220419153240.11549-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-19 15:32:40 +00:00
u32 supported, funcs, ept, vpid, ign, low, high;
x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs Add an entry in struct cpuinfo_x86 to track VMX capabilities and fill the capabilities during IA32_FEAT_CTL MSR initialization. Make the VMX capabilities dependent on IA32_FEAT_CTL and X86_FEATURE_NAMES so as to avoid unnecessary overhead on CPUs that can't possibly support VMX, or when /proc/cpuinfo is not available. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-11-sean.j.christopherson@intel.com
2019-12-21 04:45:04 +00:00
BUILD_BUG_ON(NVMXINTS != NR_VMX_FEATURE_WORDS);
/*
* The high bits contain the allowed-1 settings, i.e. features that can
* be turned on. The low bits contain the allowed-0 settings, i.e.
* features that can be turned off. Ignore the allowed-0 settings,
* if a feature can be turned on then it's supported.
*
* Use raw rdmsr() for primary processor controls and pin controls MSRs
* as they exist on any CPU that supports VMX, i.e. we want the WARN if
* the RDMSR faults.
*/
rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, ign, supported);
c->vmx_capability[PRIMARY_CTLS] = supported;
rdmsr_safe(MSR_IA32_VMX_PROCBASED_CTLS2, &ign, &supported);
c->vmx_capability[SECONDARY_CTLS] = supported;
x86/cpu: Add new VMX feature, Tertiary VM-Execution control A new 64-bit control field "tertiary processor-based VM-execution controls", is defined [1]. It's controlled by bit 17 of the primary processor-based VM-execution controls. Different from its brother VM-execution fields, this tertiary VM- execution controls field is 64 bit. So it occupies 2 vmx_feature_leafs, TERTIARY_CTLS_LOW and TERTIARY_CTLS_HIGH. Its companion VMX capability reporting MSR,MSR_IA32_VMX_PROCBASED_CTLS3 (0x492), is also semantically different from its brothers, whose 64 bits consist of all allow-1, rather than 32-bit allow-0 and 32-bit allow-1 [1][2]. Therefore, its init_vmx_capabilities() is a little different from others. [1] ISE 6.2 "VMCS Changes" https://www.intel.com/content/www/us/en/develop/download/intel-architecture-instruction-set-extensions-programming-reference.html [2] SDM Vol3. Appendix A.3 Reviewed-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Robert Hoo <robert.hu@linux.intel.com> Signed-off-by: Zeng Guang <guang.zeng@intel.com> Message-Id: <20220419153240.11549-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-19 15:32:40 +00:00
/* All 64 bits of tertiary controls MSR are allowed-1 settings. */
rdmsr_safe(MSR_IA32_VMX_PROCBASED_CTLS3, &low, &high);
c->vmx_capability[TERTIARY_CTLS_LOW] = low;
c->vmx_capability[TERTIARY_CTLS_HIGH] = high;
x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs Add an entry in struct cpuinfo_x86 to track VMX capabilities and fill the capabilities during IA32_FEAT_CTL MSR initialization. Make the VMX capabilities dependent on IA32_FEAT_CTL and X86_FEATURE_NAMES so as to avoid unnecessary overhead on CPUs that can't possibly support VMX, or when /proc/cpuinfo is not available. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-11-sean.j.christopherson@intel.com
2019-12-21 04:45:04 +00:00
rdmsr(MSR_IA32_VMX_PINBASED_CTLS, ign, supported);
rdmsr_safe(MSR_IA32_VMX_VMFUNC, &ign, &funcs);
/*
* Except for EPT+VPID, which enumerates support for both in a single
* MSR, low for EPT, high for VPID.
*/
rdmsr_safe(MSR_IA32_VMX_EPT_VPID_CAP, &ept, &vpid);
/* Pin, EPT, VPID and VM-Func are merged into a single word. */
WARN_ON_ONCE(supported >> 16);
WARN_ON_ONCE(funcs >> 4);
c->vmx_capability[MISC_FEATURES] = (supported & 0xffff) |
((vpid & 0x1) << 16) |
((funcs & 0xf) << 28);
/* EPT bits are full on scattered and must be manually handled. */
if (ept & VMX_EPT_EXECUTE_ONLY_BIT)
c->vmx_capability[MISC_FEATURES] |= VMX_F(EPT_EXECUTE_ONLY);
if (ept & VMX_EPT_AD_BIT)
c->vmx_capability[MISC_FEATURES] |= VMX_F(EPT_AD);
if (ept & VMX_EPT_1GB_PAGE_BIT)
c->vmx_capability[MISC_FEATURES] |= VMX_F(EPT_1GB);
x86/cpu: Add a VMX flag to enumerate 5-level EPT support to userspace Add a VMX flag in /proc/cpuinfo, ept_5level, so that userspace can query whether or not the CPU supports 5-level EPT paging. EPT capabilities are enumerated via MSR, i.e. aren't accessible to userspace without help from the kernel, and knowing whether or not 5-level EPT is supported is useful for debug, triage, testing, etc. For example, when EPT is enabled, bits 51:48 of guest physical addresses are consumed by the CPU if and only if 5-level EPT is enabled. For CPUs with MAXPHYADDR > 48, KVM *can't* map all legal guest memory without 5-level EPT, making 5-level EPT support valuable information for userspace. Reported-by: Yi Lai <yi1.lai@intel.com> Cc: Tao Su <tao1.su@linux.intel.com> Cc: Xudong Hao <xudong.hao@intel.com> Link: https://lore.kernel.org/r/20240110002340.485595-1-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-01-10 00:23:40 +00:00
if (ept & VMX_EPT_PAGE_WALK_5_BIT)
c->vmx_capability[MISC_FEATURES] |= VMX_F(EPT_5LEVEL);
x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs Add an entry in struct cpuinfo_x86 to track VMX capabilities and fill the capabilities during IA32_FEAT_CTL MSR initialization. Make the VMX capabilities dependent on IA32_FEAT_CTL and X86_FEATURE_NAMES so as to avoid unnecessary overhead on CPUs that can't possibly support VMX, or when /proc/cpuinfo is not available. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-11-sean.j.christopherson@intel.com
2019-12-21 04:45:04 +00:00
/* Synthetic APIC features that are aggregates of multiple features. */
if ((c->vmx_capability[PRIMARY_CTLS] & VMX_F(VIRTUAL_TPR)) &&
(c->vmx_capability[SECONDARY_CTLS] & VMX_F(VIRT_APIC_ACCESSES)))
c->vmx_capability[MISC_FEATURES] |= VMX_F(FLEXPRIORITY);
if ((c->vmx_capability[PRIMARY_CTLS] & VMX_F(VIRTUAL_TPR)) &&
(c->vmx_capability[SECONDARY_CTLS] & VMX_F(APIC_REGISTER_VIRT)) &&
(c->vmx_capability[SECONDARY_CTLS] & VMX_F(VIRT_INTR_DELIVERY)) &&
(c->vmx_capability[MISC_FEATURES] & VMX_F(POSTED_INTR)))
c->vmx_capability[MISC_FEATURES] |= VMX_F(APICV);
x86/cpu: Set synthetic VMX cpufeatures during init_ia32_feat_ctl() Set the synthetic VMX cpufeatures, which need to be kept to preserve /proc/cpuinfo's ABI, in the common IA32_FEAT_CTL initialization code. Remove the vendor code that manually sets the synthetic flags. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-13-sean.j.christopherson@intel.com
2019-12-21 04:45:06 +00:00
/* Set the synthetic cpufeatures to preserve /proc/cpuinfo's ABI. */
if (c->vmx_capability[PRIMARY_CTLS] & VMX_F(VIRTUAL_TPR))
set_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
if (c->vmx_capability[MISC_FEATURES] & VMX_F(FLEXPRIORITY))
set_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
if (c->vmx_capability[MISC_FEATURES] & VMX_F(VIRTUAL_NMIS))
set_cpu_cap(c, X86_FEATURE_VNMI);
if (c->vmx_capability[SECONDARY_CTLS] & VMX_F(EPT))
set_cpu_cap(c, X86_FEATURE_EPT);
if (c->vmx_capability[MISC_FEATURES] & VMX_F(EPT_AD))
set_cpu_cap(c, X86_FEATURE_EPT_AD);
if (c->vmx_capability[MISC_FEATURES] & VMX_F(VPID))
set_cpu_cap(c, X86_FEATURE_VPID);
x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs Add an entry in struct cpuinfo_x86 to track VMX capabilities and fill the capabilities during IA32_FEAT_CTL MSR initialization. Make the VMX capabilities dependent on IA32_FEAT_CTL and X86_FEATURE_NAMES so as to avoid unnecessary overhead on CPUs that can't possibly support VMX, or when /proc/cpuinfo is not available. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-11-sean.j.christopherson@intel.com
2019-12-21 04:45:04 +00:00
}
#endif /* CONFIG_X86_VMX_FEATURE_NAMES */
x86/cpu/intel: Add a nosgx kernel parameter Add a kernel parameter to disable SGX kernel support and document it. [ bp: Massage. ] Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Acked-by: Jethro Beekman <jethro@fortanix.com> Tested-by: Sean Christopherson <sean.j.christopherson@intel.com> Link: https://lkml.kernel.org/r/20201112220135.165028-9-jarkko@kernel.org
2020-11-12 22:01:19 +00:00
static int __init nosgx(char *str)
{
x86/cpufeatures: Make SGX_LC feature bit depend on SGX bit Move SGX_LC feature bit to CPUID dependency table to make clearing all SGX feature bits easier. Also remove clear_sgx_caps() since it is just a wrapper of setup_clear_cpu_cap(X86_FEATURE_SGX) now. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Sean Christopherson <seanjc@google.com> Acked-by: Dave Hansen <dave.hansen@intel.com> Acked-by: Jarkko Sakkinen <jarkko@kernel.org> Link: https://lkml.kernel.org/r/5d4220fd0a39f52af024d3fa166231c1d498dd10.1616136308.git.kai.huang@intel.com
2021-03-19 07:22:17 +00:00
setup_clear_cpu_cap(X86_FEATURE_SGX);
x86/cpu/intel: Add a nosgx kernel parameter Add a kernel parameter to disable SGX kernel support and document it. [ bp: Massage. ] Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Acked-by: Jethro Beekman <jethro@fortanix.com> Tested-by: Sean Christopherson <sean.j.christopherson@intel.com> Link: https://lkml.kernel.org/r/20201112220135.165028-9-jarkko@kernel.org
2020-11-12 22:01:19 +00:00
return 0;
}
early_param("nosgx", nosgx);
x86/intel: Initialize IA32_FEAT_CTL MSR at boot Opportunistically initialize IA32_FEAT_CTL to enable VMX when the MSR is left unlocked by BIOS. Configuring feature control at boot time paves the way for similar enabling of other features, e.g. Software Guard Extensions (SGX). Temporarily leave equivalent KVM code in place in order to avoid introducing a regression on Centaur and Zhaoxin CPUs, e.g. removing KVM's code would leave the MSR unlocked on those CPUs and would break existing functionality if people are loading kvm_intel on Centaur and/or Zhaoxin. Defer enablement of the boot-time configuration on Centaur and Zhaoxin to future patches to aid bisection. Note, Local Machine Check Exceptions (LMCE) are also supported by the kernel and enabled via feature control, but the kernel currently uses LMCE if and only if the feature is explicitly enabled by BIOS. Keep the current behavior to avoid introducing bugs, future patches can opt in to opportunistic enabling if it's deemed desirable to do so. Always lock IA32_FEAT_CTL if it exists, even if the CPU doesn't support VMX, so that other existing and future kernel code that queries the MSR can assume it's locked. Start from a clean slate when constructing the value to write to IA32_FEAT_CTL, i.e. ignore whatever value BIOS left in the MSR so as not to enable random features or fault on the WRMSR. Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-5-sean.j.christopherson@intel.com
2019-12-21 04:44:58 +00:00
void init_ia32_feat_ctl(struct cpuinfo_x86 *c)
{
x86/cpu/intel: Allow SGX virtualization without Launch Control support The kernel will currently disable all SGX support if the hardware does not support launch control. Make it more permissive to allow SGX virtualization on systems without Launch Control support. This will allow KVM to expose SGX to guests that have less-strict requirements on the availability of flexible launch control. Improve error message to distinguish between three cases. There are two cases where SGX support is completely disabled: 1) SGX has been disabled completely by the BIOS 2) SGX LC is locked by the BIOS. Bare-metal support is disabled because of LC unavailability. SGX virtualization is unavailable (because of Kconfig). One where it is partially available: 3) SGX LC is locked by the BIOS. Bare-metal support is disabled because of LC unavailability. SGX virtualization is supported. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jarkko Sakkinen <jarkko@kernel.org> Acked-by: Dave Hansen <dave.hansen@intel.com> Link: https://lkml.kernel.org/r/b3329777076509b3b601550da288c8f3c406a865.1616136308.git.kai.huang@intel.com
2021-03-19 07:22:58 +00:00
bool enable_sgx_kvm = false, enable_sgx_driver = false;
x86/cpu: Clear VMX feature flag if VMX is not fully enabled Now that IA32_FEAT_CTL is always configured and locked for CPUs that are known to support VMX[*], clear the VMX capability flag if the MSR is unsupported or BIOS disabled VMX, i.e. locked IA32_FEAT_CTL and didn't set the appropriate VMX enable bit. [*] Because init_ia32_feat_ctl() is called from vendors ->c_init(), it's still possible for IA32_FEAT_CTL to be left unlocked when VMX is supported by the CPU. This is not fatal, and will be addressed in a future patch. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-9-sean.j.christopherson@intel.com
2019-12-21 04:45:02 +00:00
bool tboot = tboot_enabled();
x86/cpu/intel: Allow SGX virtualization without Launch Control support The kernel will currently disable all SGX support if the hardware does not support launch control. Make it more permissive to allow SGX virtualization on systems without Launch Control support. This will allow KVM to expose SGX to guests that have less-strict requirements on the availability of flexible launch control. Improve error message to distinguish between three cases. There are two cases where SGX support is completely disabled: 1) SGX has been disabled completely by the BIOS 2) SGX LC is locked by the BIOS. Bare-metal support is disabled because of LC unavailability. SGX virtualization is unavailable (because of Kconfig). One where it is partially available: 3) SGX LC is locked by the BIOS. Bare-metal support is disabled because of LC unavailability. SGX virtualization is supported. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jarkko Sakkinen <jarkko@kernel.org> Acked-by: Dave Hansen <dave.hansen@intel.com> Link: https://lkml.kernel.org/r/b3329777076509b3b601550da288c8f3c406a865.1616136308.git.kai.huang@intel.com
2021-03-19 07:22:58 +00:00
bool enable_vmx;
x86/intel: Initialize IA32_FEAT_CTL MSR at boot Opportunistically initialize IA32_FEAT_CTL to enable VMX when the MSR is left unlocked by BIOS. Configuring feature control at boot time paves the way for similar enabling of other features, e.g. Software Guard Extensions (SGX). Temporarily leave equivalent KVM code in place in order to avoid introducing a regression on Centaur and Zhaoxin CPUs, e.g. removing KVM's code would leave the MSR unlocked on those CPUs and would break existing functionality if people are loading kvm_intel on Centaur and/or Zhaoxin. Defer enablement of the boot-time configuration on Centaur and Zhaoxin to future patches to aid bisection. Note, Local Machine Check Exceptions (LMCE) are also supported by the kernel and enabled via feature control, but the kernel currently uses LMCE if and only if the feature is explicitly enabled by BIOS. Keep the current behavior to avoid introducing bugs, future patches can opt in to opportunistic enabling if it's deemed desirable to do so. Always lock IA32_FEAT_CTL if it exists, even if the CPU doesn't support VMX, so that other existing and future kernel code that queries the MSR can assume it's locked. Start from a clean slate when constructing the value to write to IA32_FEAT_CTL, i.e. ignore whatever value BIOS left in the MSR so as not to enable random features or fault on the WRMSR. Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-5-sean.j.christopherson@intel.com
2019-12-21 04:44:58 +00:00
u64 msr;
x86/cpu: Clear VMX feature flag if VMX is not fully enabled Now that IA32_FEAT_CTL is always configured and locked for CPUs that are known to support VMX[*], clear the VMX capability flag if the MSR is unsupported or BIOS disabled VMX, i.e. locked IA32_FEAT_CTL and didn't set the appropriate VMX enable bit. [*] Because init_ia32_feat_ctl() is called from vendors ->c_init(), it's still possible for IA32_FEAT_CTL to be left unlocked when VMX is supported by the CPU. This is not fatal, and will be addressed in a future patch. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-9-sean.j.christopherson@intel.com
2019-12-21 04:45:02 +00:00
if (rdmsrl_safe(MSR_IA32_FEAT_CTL, &msr)) {
clear_cpu_cap(c, X86_FEATURE_VMX);
x86/cpufeatures: Make SGX_LC feature bit depend on SGX bit Move SGX_LC feature bit to CPUID dependency table to make clearing all SGX feature bits easier. Also remove clear_sgx_caps() since it is just a wrapper of setup_clear_cpu_cap(X86_FEATURE_SGX) now. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Sean Christopherson <seanjc@google.com> Acked-by: Dave Hansen <dave.hansen@intel.com> Acked-by: Jarkko Sakkinen <jarkko@kernel.org> Link: https://lkml.kernel.org/r/5d4220fd0a39f52af024d3fa166231c1d498dd10.1616136308.git.kai.huang@intel.com
2021-03-19 07:22:17 +00:00
clear_cpu_cap(c, X86_FEATURE_SGX);
x86/intel: Initialize IA32_FEAT_CTL MSR at boot Opportunistically initialize IA32_FEAT_CTL to enable VMX when the MSR is left unlocked by BIOS. Configuring feature control at boot time paves the way for similar enabling of other features, e.g. Software Guard Extensions (SGX). Temporarily leave equivalent KVM code in place in order to avoid introducing a regression on Centaur and Zhaoxin CPUs, e.g. removing KVM's code would leave the MSR unlocked on those CPUs and would break existing functionality if people are loading kvm_intel on Centaur and/or Zhaoxin. Defer enablement of the boot-time configuration on Centaur and Zhaoxin to future patches to aid bisection. Note, Local Machine Check Exceptions (LMCE) are also supported by the kernel and enabled via feature control, but the kernel currently uses LMCE if and only if the feature is explicitly enabled by BIOS. Keep the current behavior to avoid introducing bugs, future patches can opt in to opportunistic enabling if it's deemed desirable to do so. Always lock IA32_FEAT_CTL if it exists, even if the CPU doesn't support VMX, so that other existing and future kernel code that queries the MSR can assume it's locked. Start from a clean slate when constructing the value to write to IA32_FEAT_CTL, i.e. ignore whatever value BIOS left in the MSR so as not to enable random features or fault on the WRMSR. Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-5-sean.j.christopherson@intel.com
2019-12-21 04:44:58 +00:00
return;
x86/cpu: Clear VMX feature flag if VMX is not fully enabled Now that IA32_FEAT_CTL is always configured and locked for CPUs that are known to support VMX[*], clear the VMX capability flag if the MSR is unsupported or BIOS disabled VMX, i.e. locked IA32_FEAT_CTL and didn't set the appropriate VMX enable bit. [*] Because init_ia32_feat_ctl() is called from vendors ->c_init(), it's still possible for IA32_FEAT_CTL to be left unlocked when VMX is supported by the CPU. This is not fatal, and will be addressed in a future patch. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-9-sean.j.christopherson@intel.com
2019-12-21 04:45:02 +00:00
}
x86/intel: Initialize IA32_FEAT_CTL MSR at boot Opportunistically initialize IA32_FEAT_CTL to enable VMX when the MSR is left unlocked by BIOS. Configuring feature control at boot time paves the way for similar enabling of other features, e.g. Software Guard Extensions (SGX). Temporarily leave equivalent KVM code in place in order to avoid introducing a regression on Centaur and Zhaoxin CPUs, e.g. removing KVM's code would leave the MSR unlocked on those CPUs and would break existing functionality if people are loading kvm_intel on Centaur and/or Zhaoxin. Defer enablement of the boot-time configuration on Centaur and Zhaoxin to future patches to aid bisection. Note, Local Machine Check Exceptions (LMCE) are also supported by the kernel and enabled via feature control, but the kernel currently uses LMCE if and only if the feature is explicitly enabled by BIOS. Keep the current behavior to avoid introducing bugs, future patches can opt in to opportunistic enabling if it's deemed desirable to do so. Always lock IA32_FEAT_CTL if it exists, even if the CPU doesn't support VMX, so that other existing and future kernel code that queries the MSR can assume it's locked. Start from a clean slate when constructing the value to write to IA32_FEAT_CTL, i.e. ignore whatever value BIOS left in the MSR so as not to enable random features or fault on the WRMSR. Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-5-sean.j.christopherson@intel.com
2019-12-21 04:44:58 +00:00
x86/cpu/intel: Allow SGX virtualization without Launch Control support The kernel will currently disable all SGX support if the hardware does not support launch control. Make it more permissive to allow SGX virtualization on systems without Launch Control support. This will allow KVM to expose SGX to guests that have less-strict requirements on the availability of flexible launch control. Improve error message to distinguish between three cases. There are two cases where SGX support is completely disabled: 1) SGX has been disabled completely by the BIOS 2) SGX LC is locked by the BIOS. Bare-metal support is disabled because of LC unavailability. SGX virtualization is unavailable (because of Kconfig). One where it is partially available: 3) SGX LC is locked by the BIOS. Bare-metal support is disabled because of LC unavailability. SGX virtualization is supported. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jarkko Sakkinen <jarkko@kernel.org> Acked-by: Dave Hansen <dave.hansen@intel.com> Link: https://lkml.kernel.org/r/b3329777076509b3b601550da288c8f3c406a865.1616136308.git.kai.huang@intel.com
2021-03-19 07:22:58 +00:00
enable_vmx = cpu_has(c, X86_FEATURE_VMX) &&
IS_ENABLED(CONFIG_KVM_INTEL);
if (cpu_has(c, X86_FEATURE_SGX) && IS_ENABLED(CONFIG_X86_SGX)) {
/*
* Separate out SGX driver enabling from KVM. This allows KVM
* guests to use SGX even if the kernel SGX driver refuses to
* use it. This happens if flexible Launch Control is not
* available.
*/
enable_sgx_driver = cpu_has(c, X86_FEATURE_SGX_LC);
enable_sgx_kvm = enable_vmx && IS_ENABLED(CONFIG_X86_SGX_KVM);
}
x86/cpu/intel: Detect SGX support Kernel support for SGX is ultimately decided by the state of the launch control bits in the feature control MSR (MSR_IA32_FEAT_CTL). If the hardware supports SGX, but neglects to support flexible launch control, the kernel will not enable SGX. Enable SGX at feature control MSR initialization and update the associated X86_FEATURE flags accordingly. Disable X86_FEATURE_SGX (and all derivatives) if the kernel is not able to establish itself as the authority over SGX Launch Control. All checks are performed for each logical CPU (not just boot CPU) in order to verify that MSR_IA32_FEATURE_CONTROL is correctly configured on all CPUs. All SGX code in this series expects the same configuration from all CPUs. This differs from VMX where X86_FEATURE_VMX is intentionally cleared only for the current CPU so that KVM can provide additional information if KVM fails to load like which CPU doesn't support VMX. There’s not much the kernel or an administrator can do to fix the situation, so SGX neglects to convey additional details about these kinds of failures if they occur. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jethro Beekman <jethro@fortanix.com> Link: https://lkml.kernel.org/r/20201112220135.165028-8-jarkko@kernel.org
2020-11-12 22:01:18 +00:00
x86/intel: Initialize IA32_FEAT_CTL MSR at boot Opportunistically initialize IA32_FEAT_CTL to enable VMX when the MSR is left unlocked by BIOS. Configuring feature control at boot time paves the way for similar enabling of other features, e.g. Software Guard Extensions (SGX). Temporarily leave equivalent KVM code in place in order to avoid introducing a regression on Centaur and Zhaoxin CPUs, e.g. removing KVM's code would leave the MSR unlocked on those CPUs and would break existing functionality if people are loading kvm_intel on Centaur and/or Zhaoxin. Defer enablement of the boot-time configuration on Centaur and Zhaoxin to future patches to aid bisection. Note, Local Machine Check Exceptions (LMCE) are also supported by the kernel and enabled via feature control, but the kernel currently uses LMCE if and only if the feature is explicitly enabled by BIOS. Keep the current behavior to avoid introducing bugs, future patches can opt in to opportunistic enabling if it's deemed desirable to do so. Always lock IA32_FEAT_CTL if it exists, even if the CPU doesn't support VMX, so that other existing and future kernel code that queries the MSR can assume it's locked. Start from a clean slate when constructing the value to write to IA32_FEAT_CTL, i.e. ignore whatever value BIOS left in the MSR so as not to enable random features or fault on the WRMSR. Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-5-sean.j.christopherson@intel.com
2019-12-21 04:44:58 +00:00
if (msr & FEAT_CTL_LOCKED)
x86/cpu: Clear VMX feature flag if VMX is not fully enabled Now that IA32_FEAT_CTL is always configured and locked for CPUs that are known to support VMX[*], clear the VMX capability flag if the MSR is unsupported or BIOS disabled VMX, i.e. locked IA32_FEAT_CTL and didn't set the appropriate VMX enable bit. [*] Because init_ia32_feat_ctl() is called from vendors ->c_init(), it's still possible for IA32_FEAT_CTL to be left unlocked when VMX is supported by the CPU. This is not fatal, and will be addressed in a future patch. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-9-sean.j.christopherson@intel.com
2019-12-21 04:45:02 +00:00
goto update_caps;
x86/intel: Initialize IA32_FEAT_CTL MSR at boot Opportunistically initialize IA32_FEAT_CTL to enable VMX when the MSR is left unlocked by BIOS. Configuring feature control at boot time paves the way for similar enabling of other features, e.g. Software Guard Extensions (SGX). Temporarily leave equivalent KVM code in place in order to avoid introducing a regression on Centaur and Zhaoxin CPUs, e.g. removing KVM's code would leave the MSR unlocked on those CPUs and would break existing functionality if people are loading kvm_intel on Centaur and/or Zhaoxin. Defer enablement of the boot-time configuration on Centaur and Zhaoxin to future patches to aid bisection. Note, Local Machine Check Exceptions (LMCE) are also supported by the kernel and enabled via feature control, but the kernel currently uses LMCE if and only if the feature is explicitly enabled by BIOS. Keep the current behavior to avoid introducing bugs, future patches can opt in to opportunistic enabling if it's deemed desirable to do so. Always lock IA32_FEAT_CTL if it exists, even if the CPU doesn't support VMX, so that other existing and future kernel code that queries the MSR can assume it's locked. Start from a clean slate when constructing the value to write to IA32_FEAT_CTL, i.e. ignore whatever value BIOS left in the MSR so as not to enable random features or fault on the WRMSR. Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-5-sean.j.christopherson@intel.com
2019-12-21 04:44:58 +00:00
/*
* Ignore whatever value BIOS left in the MSR to avoid enabling random
* features or faulting on the WRMSR.
*/
msr = FEAT_CTL_LOCKED;
/*
* Enable VMX if and only if the kernel may do VMXON at some point,
* i.e. KVM is enabled, to avoid unnecessarily adding an attack vector
* for the kernel, e.g. using VMX to hide malicious code.
*/
x86/cpu/intel: Allow SGX virtualization without Launch Control support The kernel will currently disable all SGX support if the hardware does not support launch control. Make it more permissive to allow SGX virtualization on systems without Launch Control support. This will allow KVM to expose SGX to guests that have less-strict requirements on the availability of flexible launch control. Improve error message to distinguish between three cases. There are two cases where SGX support is completely disabled: 1) SGX has been disabled completely by the BIOS 2) SGX LC is locked by the BIOS. Bare-metal support is disabled because of LC unavailability. SGX virtualization is unavailable (because of Kconfig). One where it is partially available: 3) SGX LC is locked by the BIOS. Bare-metal support is disabled because of LC unavailability. SGX virtualization is supported. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jarkko Sakkinen <jarkko@kernel.org> Acked-by: Dave Hansen <dave.hansen@intel.com> Link: https://lkml.kernel.org/r/b3329777076509b3b601550da288c8f3c406a865.1616136308.git.kai.huang@intel.com
2021-03-19 07:22:58 +00:00
if (enable_vmx) {
x86/intel: Initialize IA32_FEAT_CTL MSR at boot Opportunistically initialize IA32_FEAT_CTL to enable VMX when the MSR is left unlocked by BIOS. Configuring feature control at boot time paves the way for similar enabling of other features, e.g. Software Guard Extensions (SGX). Temporarily leave equivalent KVM code in place in order to avoid introducing a regression on Centaur and Zhaoxin CPUs, e.g. removing KVM's code would leave the MSR unlocked on those CPUs and would break existing functionality if people are loading kvm_intel on Centaur and/or Zhaoxin. Defer enablement of the boot-time configuration on Centaur and Zhaoxin to future patches to aid bisection. Note, Local Machine Check Exceptions (LMCE) are also supported by the kernel and enabled via feature control, but the kernel currently uses LMCE if and only if the feature is explicitly enabled by BIOS. Keep the current behavior to avoid introducing bugs, future patches can opt in to opportunistic enabling if it's deemed desirable to do so. Always lock IA32_FEAT_CTL if it exists, even if the CPU doesn't support VMX, so that other existing and future kernel code that queries the MSR can assume it's locked. Start from a clean slate when constructing the value to write to IA32_FEAT_CTL, i.e. ignore whatever value BIOS left in the MSR so as not to enable random features or fault on the WRMSR. Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-5-sean.j.christopherson@intel.com
2019-12-21 04:44:58 +00:00
msr |= FEAT_CTL_VMX_ENABLED_OUTSIDE_SMX;
x86/cpu: Clear VMX feature flag if VMX is not fully enabled Now that IA32_FEAT_CTL is always configured and locked for CPUs that are known to support VMX[*], clear the VMX capability flag if the MSR is unsupported or BIOS disabled VMX, i.e. locked IA32_FEAT_CTL and didn't set the appropriate VMX enable bit. [*] Because init_ia32_feat_ctl() is called from vendors ->c_init(), it's still possible for IA32_FEAT_CTL to be left unlocked when VMX is supported by the CPU. This is not fatal, and will be addressed in a future patch. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-9-sean.j.christopherson@intel.com
2019-12-21 04:45:02 +00:00
if (tboot)
x86/intel: Initialize IA32_FEAT_CTL MSR at boot Opportunistically initialize IA32_FEAT_CTL to enable VMX when the MSR is left unlocked by BIOS. Configuring feature control at boot time paves the way for similar enabling of other features, e.g. Software Guard Extensions (SGX). Temporarily leave equivalent KVM code in place in order to avoid introducing a regression on Centaur and Zhaoxin CPUs, e.g. removing KVM's code would leave the MSR unlocked on those CPUs and would break existing functionality if people are loading kvm_intel on Centaur and/or Zhaoxin. Defer enablement of the boot-time configuration on Centaur and Zhaoxin to future patches to aid bisection. Note, Local Machine Check Exceptions (LMCE) are also supported by the kernel and enabled via feature control, but the kernel currently uses LMCE if and only if the feature is explicitly enabled by BIOS. Keep the current behavior to avoid introducing bugs, future patches can opt in to opportunistic enabling if it's deemed desirable to do so. Always lock IA32_FEAT_CTL if it exists, even if the CPU doesn't support VMX, so that other existing and future kernel code that queries the MSR can assume it's locked. Start from a clean slate when constructing the value to write to IA32_FEAT_CTL, i.e. ignore whatever value BIOS left in the MSR so as not to enable random features or fault on the WRMSR. Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-5-sean.j.christopherson@intel.com
2019-12-21 04:44:58 +00:00
msr |= FEAT_CTL_VMX_ENABLED_INSIDE_SMX;
}
x86/cpu/intel: Allow SGX virtualization without Launch Control support The kernel will currently disable all SGX support if the hardware does not support launch control. Make it more permissive to allow SGX virtualization on systems without Launch Control support. This will allow KVM to expose SGX to guests that have less-strict requirements on the availability of flexible launch control. Improve error message to distinguish between three cases. There are two cases where SGX support is completely disabled: 1) SGX has been disabled completely by the BIOS 2) SGX LC is locked by the BIOS. Bare-metal support is disabled because of LC unavailability. SGX virtualization is unavailable (because of Kconfig). One where it is partially available: 3) SGX LC is locked by the BIOS. Bare-metal support is disabled because of LC unavailability. SGX virtualization is supported. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jarkko Sakkinen <jarkko@kernel.org> Acked-by: Dave Hansen <dave.hansen@intel.com> Link: https://lkml.kernel.org/r/b3329777076509b3b601550da288c8f3c406a865.1616136308.git.kai.huang@intel.com
2021-03-19 07:22:58 +00:00
if (enable_sgx_kvm || enable_sgx_driver) {
msr |= FEAT_CTL_SGX_ENABLED;
if (enable_sgx_driver)
msr |= FEAT_CTL_SGX_LC_ENABLED;
}
x86/cpu/intel: Detect SGX support Kernel support for SGX is ultimately decided by the state of the launch control bits in the feature control MSR (MSR_IA32_FEAT_CTL). If the hardware supports SGX, but neglects to support flexible launch control, the kernel will not enable SGX. Enable SGX at feature control MSR initialization and update the associated X86_FEATURE flags accordingly. Disable X86_FEATURE_SGX (and all derivatives) if the kernel is not able to establish itself as the authority over SGX Launch Control. All checks are performed for each logical CPU (not just boot CPU) in order to verify that MSR_IA32_FEATURE_CONTROL is correctly configured on all CPUs. All SGX code in this series expects the same configuration from all CPUs. This differs from VMX where X86_FEATURE_VMX is intentionally cleared only for the current CPU so that KVM can provide additional information if KVM fails to load like which CPU doesn't support VMX. There’s not much the kernel or an administrator can do to fix the situation, so SGX neglects to convey additional details about these kinds of failures if they occur. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jethro Beekman <jethro@fortanix.com> Link: https://lkml.kernel.org/r/20201112220135.165028-8-jarkko@kernel.org
2020-11-12 22:01:18 +00:00
x86/intel: Initialize IA32_FEAT_CTL MSR at boot Opportunistically initialize IA32_FEAT_CTL to enable VMX when the MSR is left unlocked by BIOS. Configuring feature control at boot time paves the way for similar enabling of other features, e.g. Software Guard Extensions (SGX). Temporarily leave equivalent KVM code in place in order to avoid introducing a regression on Centaur and Zhaoxin CPUs, e.g. removing KVM's code would leave the MSR unlocked on those CPUs and would break existing functionality if people are loading kvm_intel on Centaur and/or Zhaoxin. Defer enablement of the boot-time configuration on Centaur and Zhaoxin to future patches to aid bisection. Note, Local Machine Check Exceptions (LMCE) are also supported by the kernel and enabled via feature control, but the kernel currently uses LMCE if and only if the feature is explicitly enabled by BIOS. Keep the current behavior to avoid introducing bugs, future patches can opt in to opportunistic enabling if it's deemed desirable to do so. Always lock IA32_FEAT_CTL if it exists, even if the CPU doesn't support VMX, so that other existing and future kernel code that queries the MSR can assume it's locked. Start from a clean slate when constructing the value to write to IA32_FEAT_CTL, i.e. ignore whatever value BIOS left in the MSR so as not to enable random features or fault on the WRMSR. Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-5-sean.j.christopherson@intel.com
2019-12-21 04:44:58 +00:00
wrmsrl(MSR_IA32_FEAT_CTL, msr);
x86/cpu: Clear VMX feature flag if VMX is not fully enabled Now that IA32_FEAT_CTL is always configured and locked for CPUs that are known to support VMX[*], clear the VMX capability flag if the MSR is unsupported or BIOS disabled VMX, i.e. locked IA32_FEAT_CTL and didn't set the appropriate VMX enable bit. [*] Because init_ia32_feat_ctl() is called from vendors ->c_init(), it's still possible for IA32_FEAT_CTL to be left unlocked when VMX is supported by the CPU. This is not fatal, and will be addressed in a future patch. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-9-sean.j.christopherson@intel.com
2019-12-21 04:45:02 +00:00
update_caps:
x86/cpufeatures: Add flag to track whether MSR IA32_FEAT_CTL is configured Add a new feature flag, X86_FEATURE_MSR_IA32_FEAT_CTL, to track whether IA32_FEAT_CTL has been initialized. This will allow KVM, and any future subsystems that depend on IA32_FEAT_CTL, to rely purely on cpufeatures to query platform support, e.g. allows a future patch to remove KVM's manual IA32_FEAT_CTL MSR checks. Various features (on platforms that support IA32_FEAT_CTL) are dependent on IA32_FEAT_CTL being configured and locked, e.g. VMX and LMCE. The MSR is always configured during boot, but only if the CPU vendor is recognized by the kernel. Because CPUID doesn't incorporate the current IA32_FEAT_CTL value in its reporting of relevant features, it's possible for a feature to be reported as supported in cpufeatures but not truly enabled, e.g. if the CPU supports VMX but the kernel doesn't recognize the CPU. As a result, without the flag, KVM would see VMX as supported even if IA32_FEAT_CTL hasn't been initialized, and so would need to manually read the MSR and check the various enabling bits to avoid taking an unexpected #GP on VMXON. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-14-sean.j.christopherson@intel.com
2019-12-21 04:45:07 +00:00
set_cpu_cap(c, X86_FEATURE_MSR_IA32_FEAT_CTL);
x86/cpu: Clear VMX feature flag if VMX is not fully enabled Now that IA32_FEAT_CTL is always configured and locked for CPUs that are known to support VMX[*], clear the VMX capability flag if the MSR is unsupported or BIOS disabled VMX, i.e. locked IA32_FEAT_CTL and didn't set the appropriate VMX enable bit. [*] Because init_ia32_feat_ctl() is called from vendors ->c_init(), it's still possible for IA32_FEAT_CTL to be left unlocked when VMX is supported by the CPU. This is not fatal, and will be addressed in a future patch. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-9-sean.j.christopherson@intel.com
2019-12-21 04:45:02 +00:00
if (!cpu_has(c, X86_FEATURE_VMX))
x86/cpu/intel: Detect SGX support Kernel support for SGX is ultimately decided by the state of the launch control bits in the feature control MSR (MSR_IA32_FEAT_CTL). If the hardware supports SGX, but neglects to support flexible launch control, the kernel will not enable SGX. Enable SGX at feature control MSR initialization and update the associated X86_FEATURE flags accordingly. Disable X86_FEATURE_SGX (and all derivatives) if the kernel is not able to establish itself as the authority over SGX Launch Control. All checks are performed for each logical CPU (not just boot CPU) in order to verify that MSR_IA32_FEATURE_CONTROL is correctly configured on all CPUs. All SGX code in this series expects the same configuration from all CPUs. This differs from VMX where X86_FEATURE_VMX is intentionally cleared only for the current CPU so that KVM can provide additional information if KVM fails to load like which CPU doesn't support VMX. There’s not much the kernel or an administrator can do to fix the situation, so SGX neglects to convey additional details about these kinds of failures if they occur. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jethro Beekman <jethro@fortanix.com> Link: https://lkml.kernel.org/r/20201112220135.165028-8-jarkko@kernel.org
2020-11-12 22:01:18 +00:00
goto update_sgx;
x86/cpu: Clear VMX feature flag if VMX is not fully enabled Now that IA32_FEAT_CTL is always configured and locked for CPUs that are known to support VMX[*], clear the VMX capability flag if the MSR is unsupported or BIOS disabled VMX, i.e. locked IA32_FEAT_CTL and didn't set the appropriate VMX enable bit. [*] Because init_ia32_feat_ctl() is called from vendors ->c_init(), it's still possible for IA32_FEAT_CTL to be left unlocked when VMX is supported by the CPU. This is not fatal, and will be addressed in a future patch. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-9-sean.j.christopherson@intel.com
2019-12-21 04:45:02 +00:00
if ( (tboot && !(msr & FEAT_CTL_VMX_ENABLED_INSIDE_SMX)) ||
(!tboot && !(msr & FEAT_CTL_VMX_ENABLED_OUTSIDE_SMX))) {
x86/cpu: Print "VMX disabled" error message iff KVM is enabled Don't print an error message about VMX being disabled by BIOS if KVM, the sole user of VMX, is disabled. E.g. if KVM is disabled and the MSR is unlocked, the kernel will intentionally disable VMX when locking feature control and then complain that "BIOS" disabled VMX. Fixes: ef4d3bf19855 ("x86/cpu: Clear VMX feature flag if VMX is not fully enabled") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200114202545.20296-1-sean.j.christopherson@intel.com
2020-01-14 20:25:45 +00:00
if (IS_ENABLED(CONFIG_KVM_INTEL))
pr_err_once("VMX (%s TXT) disabled by BIOS\n",
tboot ? "inside" : "outside");
x86/cpu: Clear VMX feature flag if VMX is not fully enabled Now that IA32_FEAT_CTL is always configured and locked for CPUs that are known to support VMX[*], clear the VMX capability flag if the MSR is unsupported or BIOS disabled VMX, i.e. locked IA32_FEAT_CTL and didn't set the appropriate VMX enable bit. [*] Because init_ia32_feat_ctl() is called from vendors ->c_init(), it's still possible for IA32_FEAT_CTL to be left unlocked when VMX is supported by the CPU. This is not fatal, and will be addressed in a future patch. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-9-sean.j.christopherson@intel.com
2019-12-21 04:45:02 +00:00
clear_cpu_cap(c, X86_FEATURE_VMX);
x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs Add an entry in struct cpuinfo_x86 to track VMX capabilities and fill the capabilities during IA32_FEAT_CTL MSR initialization. Make the VMX capabilities dependent on IA32_FEAT_CTL and X86_FEATURE_NAMES so as to avoid unnecessary overhead on CPUs that can't possibly support VMX, or when /proc/cpuinfo is not available. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-11-sean.j.christopherson@intel.com
2019-12-21 04:45:04 +00:00
} else {
#ifdef CONFIG_X86_VMX_FEATURE_NAMES
init_vmx_capabilities(c);
#endif
x86/cpu: Clear VMX feature flag if VMX is not fully enabled Now that IA32_FEAT_CTL is always configured and locked for CPUs that are known to support VMX[*], clear the VMX capability flag if the MSR is unsupported or BIOS disabled VMX, i.e. locked IA32_FEAT_CTL and didn't set the appropriate VMX enable bit. [*] Because init_ia32_feat_ctl() is called from vendors ->c_init(), it's still possible for IA32_FEAT_CTL to be left unlocked when VMX is supported by the CPU. This is not fatal, and will be addressed in a future patch. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-9-sean.j.christopherson@intel.com
2019-12-21 04:45:02 +00:00
}
x86/cpu/intel: Detect SGX support Kernel support for SGX is ultimately decided by the state of the launch control bits in the feature control MSR (MSR_IA32_FEAT_CTL). If the hardware supports SGX, but neglects to support flexible launch control, the kernel will not enable SGX. Enable SGX at feature control MSR initialization and update the associated X86_FEATURE flags accordingly. Disable X86_FEATURE_SGX (and all derivatives) if the kernel is not able to establish itself as the authority over SGX Launch Control. All checks are performed for each logical CPU (not just boot CPU) in order to verify that MSR_IA32_FEATURE_CONTROL is correctly configured on all CPUs. All SGX code in this series expects the same configuration from all CPUs. This differs from VMX where X86_FEATURE_VMX is intentionally cleared only for the current CPU so that KVM can provide additional information if KVM fails to load like which CPU doesn't support VMX. There’s not much the kernel or an administrator can do to fix the situation, so SGX neglects to convey additional details about these kinds of failures if they occur. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jethro Beekman <jethro@fortanix.com> Link: https://lkml.kernel.org/r/20201112220135.165028-8-jarkko@kernel.org
2020-11-12 22:01:18 +00:00
update_sgx:
x86/cpu/intel: Allow SGX virtualization without Launch Control support The kernel will currently disable all SGX support if the hardware does not support launch control. Make it more permissive to allow SGX virtualization on systems without Launch Control support. This will allow KVM to expose SGX to guests that have less-strict requirements on the availability of flexible launch control. Improve error message to distinguish between three cases. There are two cases where SGX support is completely disabled: 1) SGX has been disabled completely by the BIOS 2) SGX LC is locked by the BIOS. Bare-metal support is disabled because of LC unavailability. SGX virtualization is unavailable (because of Kconfig). One where it is partially available: 3) SGX LC is locked by the BIOS. Bare-metal support is disabled because of LC unavailability. SGX virtualization is supported. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jarkko Sakkinen <jarkko@kernel.org> Acked-by: Dave Hansen <dave.hansen@intel.com> Link: https://lkml.kernel.org/r/b3329777076509b3b601550da288c8f3c406a865.1616136308.git.kai.huang@intel.com
2021-03-19 07:22:58 +00:00
if (!(msr & FEAT_CTL_SGX_ENABLED)) {
if (enable_sgx_kvm || enable_sgx_driver)
pr_err_once("SGX disabled by BIOS.\n");
x86/cpufeatures: Make SGX_LC feature bit depend on SGX bit Move SGX_LC feature bit to CPUID dependency table to make clearing all SGX feature bits easier. Also remove clear_sgx_caps() since it is just a wrapper of setup_clear_cpu_cap(X86_FEATURE_SGX) now. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Sean Christopherson <seanjc@google.com> Acked-by: Dave Hansen <dave.hansen@intel.com> Acked-by: Jarkko Sakkinen <jarkko@kernel.org> Link: https://lkml.kernel.org/r/5d4220fd0a39f52af024d3fa166231c1d498dd10.1616136308.git.kai.huang@intel.com
2021-03-19 07:22:17 +00:00
clear_cpu_cap(c, X86_FEATURE_SGX);
x86/cpu/intel: Allow SGX virtualization without Launch Control support The kernel will currently disable all SGX support if the hardware does not support launch control. Make it more permissive to allow SGX virtualization on systems without Launch Control support. This will allow KVM to expose SGX to guests that have less-strict requirements on the availability of flexible launch control. Improve error message to distinguish between three cases. There are two cases where SGX support is completely disabled: 1) SGX has been disabled completely by the BIOS 2) SGX LC is locked by the BIOS. Bare-metal support is disabled because of LC unavailability. SGX virtualization is unavailable (because of Kconfig). One where it is partially available: 3) SGX LC is locked by the BIOS. Bare-metal support is disabled because of LC unavailability. SGX virtualization is supported. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jarkko Sakkinen <jarkko@kernel.org> Acked-by: Dave Hansen <dave.hansen@intel.com> Link: https://lkml.kernel.org/r/b3329777076509b3b601550da288c8f3c406a865.1616136308.git.kai.huang@intel.com
2021-03-19 07:22:58 +00:00
return;
}
/*
* VMX feature bit may be cleared due to being disabled in BIOS,
* in which case SGX virtualization cannot be supported either.
*/
if (!cpu_has(c, X86_FEATURE_VMX) && enable_sgx_kvm) {
pr_err_once("SGX virtualization disabled due to lack of VMX.\n");
enable_sgx_kvm = 0;
}
if (!(msr & FEAT_CTL_SGX_LC_ENABLED) && enable_sgx_driver) {
if (!enable_sgx_kvm) {
pr_err_once("SGX Launch Control is locked. Disable SGX.\n");
clear_cpu_cap(c, X86_FEATURE_SGX);
} else {
pr_err_once("SGX Launch Control is locked. Support SGX virtualization only.\n");
clear_cpu_cap(c, X86_FEATURE_SGX_LC);
}
x86/cpu/intel: Detect SGX support Kernel support for SGX is ultimately decided by the state of the launch control bits in the feature control MSR (MSR_IA32_FEAT_CTL). If the hardware supports SGX, but neglects to support flexible launch control, the kernel will not enable SGX. Enable SGX at feature control MSR initialization and update the associated X86_FEATURE flags accordingly. Disable X86_FEATURE_SGX (and all derivatives) if the kernel is not able to establish itself as the authority over SGX Launch Control. All checks are performed for each logical CPU (not just boot CPU) in order to verify that MSR_IA32_FEATURE_CONTROL is correctly configured on all CPUs. All SGX code in this series expects the same configuration from all CPUs. This differs from VMX where X86_FEATURE_VMX is intentionally cleared only for the current CPU so that KVM can provide additional information if KVM fails to load like which CPU doesn't support VMX. There’s not much the kernel or an administrator can do to fix the situation, so SGX neglects to convey additional details about these kinds of failures if they occur. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jethro Beekman <jethro@fortanix.com> Link: https://lkml.kernel.org/r/20201112220135.165028-8-jarkko@kernel.org
2020-11-12 22:01:18 +00:00
}
x86/intel: Initialize IA32_FEAT_CTL MSR at boot Opportunistically initialize IA32_FEAT_CTL to enable VMX when the MSR is left unlocked by BIOS. Configuring feature control at boot time paves the way for similar enabling of other features, e.g. Software Guard Extensions (SGX). Temporarily leave equivalent KVM code in place in order to avoid introducing a regression on Centaur and Zhaoxin CPUs, e.g. removing KVM's code would leave the MSR unlocked on those CPUs and would break existing functionality if people are loading kvm_intel on Centaur and/or Zhaoxin. Defer enablement of the boot-time configuration on Centaur and Zhaoxin to future patches to aid bisection. Note, Local Machine Check Exceptions (LMCE) are also supported by the kernel and enabled via feature control, but the kernel currently uses LMCE if and only if the feature is explicitly enabled by BIOS. Keep the current behavior to avoid introducing bugs, future patches can opt in to opportunistic enabling if it's deemed desirable to do so. Always lock IA32_FEAT_CTL if it exists, even if the CPU doesn't support VMX, so that other existing and future kernel code that queries the MSR can assume it's locked. Start from a clean slate when constructing the value to write to IA32_FEAT_CTL, i.e. ignore whatever value BIOS left in the MSR so as not to enable random features or fault on the WRMSR. Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-5-sean.j.christopherson@intel.com
2019-12-21 04:44:58 +00:00
}