Commit graph

23 commits

Author SHA1 Message Date
Paolo Bonzini
0378daef0c KVM/arm64 updates for Linux 5.9:
- Split the VHE and nVHE hypervisor code bases, build the EL2 code
   separately, allowing for the VHE code to now be built with instrumentation
 
 - Level-based TLB invalidation support
 
 - Restructure of the vcpu register storage to accomodate the NV code
 
 - Pointer Authentication available for guests on nVHE hosts
 
 - Simplification of the system register table parsing
 
 - MMU cleanups and fixes
 
 - A number of post-32bit cleanups and other fixes
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Merge tag 'kvmarm-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-next-5.6

KVM/arm64 updates for Linux 5.9:

- Split the VHE and nVHE hypervisor code bases, build the EL2 code
  separately, allowing for the VHE code to now be built with instrumentation

- Level-based TLB invalidation support

- Restructure of the vcpu register storage to accomodate the NV code

- Pointer Authentication available for guests on nVHE hosts

- Simplification of the system register table parsing

- MMU cleanups and fixes

- A number of post-32bit cleanups and other fixes
2020-08-09 12:58:23 -04:00
Marc Zyngier
a394cf6e85 Merge branch 'kvm-arm64/misc-5.9' into kvmarm-master/next-WIP
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-07-28 16:26:16 +01:00
Tianjia Zhang
74cc7e0c35 KVM: arm64: clean up redundant 'kvm_run' parameters
In the current kvm version, 'kvm_run' has been included in the 'kvm_vcpu'
structure. For historical reasons, many kvm-related function parameters
retain the 'kvm_run' and 'kvm_vcpu' parameters at the same time. This
patch does a unified cleanup of these remaining redundant parameters.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200623131418.31473-3-tianjia.zhang@linux.alibaba.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 04:26:40 -04:00
Sean Christopherson
e539451b7e KVM: arm64: Use common code's approach for __GFP_ZERO with memory caches
Add a "gfp_zero" member to arm64's 'struct kvm_mmu_memory_cache' to make
the struct and its usage compatible with the common 'struct
kvm_mmu_memory_cache' in linux/kvm_host.h.  This will minimize code
churn when arm64 moves to the common implementation in a future patch, at
the cost of temporarily having somewhat silly code.

Note, GFP_PGTABLE_USER is equivalent to GFP_KERNEL_ACCOUNT | GFP_ZERO:

  #define GFP_PGTABLE_USER  (GFP_PGTABLE_KERNEL | __GFP_ACCOUNT)
  |
  -> #define GFP_PGTABLE_KERNEL        (GFP_KERNEL | __GFP_ZERO)

  == GFP_KERNEL | __GFP_ACCOUNT | __GFP_ZERO

versus

  #define GFP_KERNEL_ACCOUNT (GFP_KERNEL | __GFP_ACCOUNT)

    with __GFP_ZERO explicitly OR'd in

  == GFP_KERNEL | __GFP_ACCOUNT | __GFP_ZERO

No functional change intended.

Tested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-18-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-09 13:29:43 -04:00
Marc Zyngier
3c5ff0c60f KVM: arm64: timers: Rename kvm_timer_sync_hwstate to kvm_timer_sync_user
kvm_timer_sync_hwstate() has nothing to do with the timer HW state,
but more to do with the state of a userspace interrupt controller.
Change the suffix from _hwstate to_user, in keeping with the rest
of the code.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-07-07 09:28:38 +01:00
Christoffer Dall
a0e50aa3f4 KVM: arm64: Factor out stage 2 page table data from struct kvm
As we are about to reuse our stage 2 page table manipulation code for
shadow stage 2 page tables in the context of nested virtualization, we
are going to manage multiple stage 2 page tables for a single VM.

This requires some pretty invasive changes to our data structures,
which moves the vmid and pgd pointers into a separate structure and
change pretty much all of our mmu code to operate on this structure
instead.

The new structure is called struct kvm_s2_mmu.

There is no intended functional change by this patch alone.

Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
[Designed data structure layout in collaboration]
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Co-developed-by: Marc Zyngier <maz@kernel.org>
[maz: Moved the last_vcpu_ran down to the S2 MMU structure as well]
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-07-07 09:28:37 +01:00
Peng Hao
95fa0ba83e KVM: arm64: Drop long gone function parameter documentation
update_vmid() just has one parameter "vmid".The other parameter
"kvm" is no longer used.

Signed-off-by: Peng Hao <richard.peng@oppo.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200701120709.388377-1-richard.peng@oppo.com
2020-07-05 20:51:56 +01:00
David Brazdil
13aeb9b400 KVM: arm64: Split hyp/sysreg-sr.c to VHE/nVHE
sysreg-sr.c contains KVM's code for saving/restoring system registers, with
some code shared between VHE/nVHE. These common routines are moved to
a header file, VHE-specific code is moved to vhe/sysreg-sr.c and nVHE-specific
code to nvhe/sysreg-sr.c.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-12-dbrazdil@google.com
2020-07-05 18:38:29 +01:00
David Brazdil
09cf57eba3 KVM: arm64: Split hyp/switch.c to VHE/nVHE
switch.c implements context-switching for KVM, with large parts shared between
VHE/nVHE. These common routines are moved to a header file, VHE-specific code
is moved to vhe/switch.c and nVHE-specific code is moved to nvhe/switch.c.

Previously __kvm_vcpu_run needed a different symbol name for VHE/nVHE. This
is cleaned up and the caller in arm.c simplified.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-10-dbrazdil@google.com
2020-07-05 18:38:21 +01:00
David Brazdil
b877e9849d KVM: arm64: Build hyp-entry.S separately for VHE/nVHE
hyp-entry.S contains implementation of KVM hyp vectors. This code is mostly
shared between VHE/nVHE, therefore compile it under both VHE and nVHE build
rules. nVHE-specific host HVC handler is hidden behind __KVM_NVHE_HYPERVISOR__.

Adjust code which selects which KVM hyp vecs to install to choose the correct
VHE/nVHE symbol.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-7-dbrazdil@google.com
2020-07-05 18:38:08 +01:00
Paolo Bonzini
49b3deaad3 KVM/arm64 fixes for Linux 5.8, take #1
* 32bit VM fixes:
   - Fix embarassing mapping issue between AArch32 CSSELR and AArch64
     ACTLR
   - Add ACTLR2 support for AArch32
   - Get rid of the useless ACTLR_EL1 save/restore
   - Fix CP14/15 accesses for AArch32 guests on BE hosts
   - Ensure that we don't loose any state when injecting a 32bit
     exception when running on a VHE host
 
 * 64bit VM fixes:
   - Fix PtrAuth host saving happening in preemptible contexts
   - Optimize PtrAuth lazy enable
   - Drop vcpu to cpu context pointer
   - Fix sparse warnings for HYP per-CPU accesses
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Merge tag 'kvmarm-fixes-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for Linux 5.8, take #1

* 32bit VM fixes:
  - Fix embarassing mapping issue between AArch32 CSSELR and AArch64
    ACTLR
  - Add ACTLR2 support for AArch32
  - Get rid of the useless ACTLR_EL1 save/restore
  - Fix CP14/15 accesses for AArch32 guests on BE hosts
  - Ensure that we don't loose any state when injecting a 32bit
    exception when running on a VHE host

* 64bit VM fixes:
  - Fix PtrAuth host saving happening in preemptible contexts
  - Optimize PtrAuth lazy enable
  - Drop vcpu to cpu context pointer
  - Fix sparse warnings for HYP per-CPU accesses
2020-06-11 14:02:32 -04:00
Marc Zyngier
07da1ffaa1 KVM: arm64: Remove host_cpu_context member from vcpu structure
For very long, we have kept this pointer back to the per-cpu
host state, despite having working per-cpu accessors at EL2
for some time now.

Recent investigations have shown that this pointer is easy
to abuse in preemptible context, which is a sure sign that
it would better be gone. Not to mention that a per-cpu
pointer is faster to access at all times.

Reported-by: Andrew Scull <ascull@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com
Reviewed-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-06-09 10:59:52 +01:00
Marc Zyngier
29eb5a3c57 KVM: arm64: Handle PtrAuth traps early
The current way we deal with PtrAuth is a bit heavy handed:

- We forcefully save the host's keys on each vcpu_load()
- Handling the PtrAuth trap forces us to go all the way back
  to the exit handling code to just set the HCR bits

Overall, this is pretty cumbersome. A better approach would be
to handle it the same way we deal with the FPSIMD registers:

- On vcpu_load() disable PtrAuth for the guest
- On first use, save the host's keys, enable PtrAuth in the
  guest

Crucially, this can happen as a fixup, which is done very early
on exit. We can then reenter the guest immediately without
leaving the hypervisor role.

Another thing is that it simplify the rest of the host handling:
exiting all the way to the host means that the only possible
outcome for this trap is to inject an UNDEF.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-06-09 10:59:52 +01:00
Marc Zyngier
ef3e40a7ea KVM: arm64: Save the host's PtrAuth keys in non-preemptible context
When using the PtrAuth feature in a guest, we need to save the host's
keys before allowing the guest to program them. For that, we dump
them in a per-CPU data structure (the so called host context).

But both call sites that do this are in preemptible context,
which may end up in disaster should the vcpu thread get preempted
before reentering the guest.

Instead, save the keys eagerly on each vcpu_load(). This has an
increased overhead, but is at least safe.

Cc: stable@vger.kernel.org
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-06-09 10:44:40 +01:00
Paolo Bonzini
d56f5136b0 KVM: let kvm_destroy_vm_debugfs clean up vCPU debugfs directories
After commit 63d0434 ("KVM: x86: move kvm_create_vcpu_debugfs after
last failure point") we are creating the pre-vCPU debugfs files
after the creation of the vCPU file descriptor.  This makes it
possible for userspace to reach kvm_vcpu_release before
kvm_create_vcpu_debugfs has finished.  The vcpu->debugfs_dentry
then does not have any associated inode anymore, and this causes
a NULL-pointer dereference in debugfs_create_file.

The solution is simply to avoid removing the files; they are
cleaned up when the VM file descriptor is closed (and that must be
after KVM_CREATE_VCPU returns).  We can stop storing the dentry
in struct kvm_vcpu too, because it is not needed anywhere after
kvm_create_vcpu_debugfs returns.

Reported-by: syzbot+705f4401d5a93a59b87d@syzkaller.appspotmail.com
Fixes: 63d0434837 ("KVM: x86: move kvm_create_vcpu_debugfs after last failure point")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-04 11:00:54 -04:00
Linus Torvalds
039aeb9deb ARM:
- Move the arch-specific code into arch/arm64/kvm
 - Start the post-32bit cleanup
 - Cherry-pick a few non-invasive pre-NV patches
 
 x86:
 - Rework of TLB flushing
 - Rework of event injection, especially with respect to nested virtualization
 - Nested AMD event injection facelift, building on the rework of generic code
 and fixing a lot of corner cases
 - Nested AMD live migration support
 - Optimization for TSC deadline MSR writes and IPIs
 - Various cleanups
 - Asynchronous page fault cleanups (from tglx, common topic branch with tip tree)
 - Interrupt-based delivery of asynchronous "page ready" events (host side)
 - Hyper-V MSRs and hypercalls for guest debugging
 - VMX preemption timer fixes
 
 s390:
 - Cleanups
 
 Generic:
 - switch vCPU thread wakeup from swait to rcuwait
 
 The other architectures, and the guest side of the asynchronous page fault
 work, will come next week.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM:
   - Move the arch-specific code into arch/arm64/kvm

   - Start the post-32bit cleanup

   - Cherry-pick a few non-invasive pre-NV patches

  x86:
   - Rework of TLB flushing

   - Rework of event injection, especially with respect to nested
     virtualization

   - Nested AMD event injection facelift, building on the rework of
     generic code and fixing a lot of corner cases

   - Nested AMD live migration support

   - Optimization for TSC deadline MSR writes and IPIs

   - Various cleanups

   - Asynchronous page fault cleanups (from tglx, common topic branch
     with tip tree)

   - Interrupt-based delivery of asynchronous "page ready" events (host
     side)

   - Hyper-V MSRs and hypercalls for guest debugging

   - VMX preemption timer fixes

  s390:
   - Cleanups

  Generic:
   - switch vCPU thread wakeup from swait to rcuwait

  The other architectures, and the guest side of the asynchronous page
  fault work, will come next week"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (256 commits)
  KVM: selftests: fix rdtsc() for vmx_tsc_adjust_test
  KVM: check userspace_addr for all memslots
  KVM: selftests: update hyperv_cpuid with SynDBG tests
  x86/kvm/hyper-v: Add support for synthetic debugger via hypercalls
  x86/kvm/hyper-v: enable hypercalls regardless of hypercall page
  x86/kvm/hyper-v: Add support for synthetic debugger interface
  x86/hyper-v: Add synthetic debugger definitions
  KVM: selftests: VMX preemption timer migration test
  KVM: nVMX: Fix VMX preemption timer migration
  x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit
  KVM: x86/pmu: Support full width counting
  KVM: x86/pmu: Tweak kvm_pmu_get_msr to pass 'struct msr_data' in
  KVM: x86: announce KVM_FEATURE_ASYNC_PF_INT
  KVM: x86: acknowledgment mechanism for async pf page ready notifications
  KVM: x86: interrupt based APF 'page ready' event delivery
  KVM: introduce kvm_read_guest_offset_cached()
  KVM: rename kvm_arch_can_inject_async_page_present() to kvm_arch_can_dequeue_async_page_present()
  KVM: x86: extend struct kvm_vcpu_pv_apf_data with token info
  Revert "KVM: async_pf: Fix #DF due to inject "Page not Present" and "Page Ready" exceptions simultaneously"
  KVM: VMX: Replace zero-length array with flexible-array
  ...
2020-06-03 15:13:47 -07:00
Paolo Bonzini
380609445c KVM/arm64 updates for Linux 5.8:
- Move the arch-specific code into arch/arm64/kvm
 - Start the post-32bit cleanup
 - Cherry-pick a few non-invasive pre-NV patches
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Merge tag 'kvmarm-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for Linux 5.8:

- Move the arch-specific code into arch/arm64/kvm
- Start the post-32bit cleanup
- Cherry-pick a few non-invasive pre-NV patches
2020-06-01 04:26:27 -04:00
Marc Zyngier
7ae2f3db61 KVM: arm64: Flush the instruction cache if not unmapping the VM on reboot
On a system with FWB, we don't need to unmap Stage-2 on reboot,
as even if userspace takes this opportunity to repaint the whole
of memory, FWB ensures that the data side stays consistent even
if the guest uses non-cacheable mappings.

However, the I-side is not necessarily coherent with the D-side
if CTR_EL0.DIC is 0. In this case, invalidate the i-cache to
preserve coherency.

Reported-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Fixes: 892713e97c ("KVM: arm64: Sidestep stage2_unmap_vm() on vcpu reset when S2FWB is supported")
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-05-31 11:31:54 +01:00
David Brazdil
71b3ec5f22 KVM: arm64: Clean up cpu_init_hyp_mode()
Pull bits of code to the only place where it is used. Remove empty function
__cpu_init_stage2(). Remove redundant has_vhe() check since this function is
nVHE-only. No functional changes intended.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200515152056.83158-1-dbrazdil@google.com
2020-05-25 16:15:47 +01:00
Marc Zyngier
5107000faa KVM: arm64: Make KVM_CAP_MAX_VCPUS compatible with the selected GIC version
KVM_CAP_MAX_VCPUS always return the maximum possible number of
VCPUs, irrespective of the selected interrupt controller. This
is pretty misleading for userspace that selects a GICv2 on a GICv3
system that supports v2 compat: It always gets a maximum of 512
VCPUs, even if the effective limit is 8. The 9th VCPU will fail
to be created, which is unexpected as far as userspace is concerned.

Fortunately, we already have the right information stashed in the
kvm structure, and we can return it as requested.

Reported-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20200427141507.284985-1-maz@kernel.org
2020-05-16 15:05:02 +01:00
Zenghui Yu
892713e97c KVM: arm64: Sidestep stage2_unmap_vm() on vcpu reset when S2FWB is supported
stage2_unmap_vm() was introduced to unmap user RAM region in the stage2
page table to make the caches coherent. E.g., a guest reboot with stage1
MMU disabled will access memory using non-cacheable attributes. If the
RAM and caches are not coherent at this stage, some evicted dirty cache
line may go and corrupt guest data in RAM.

Since ARMv8.4, S2FWB feature is mandatory and KVM will take advantage
of it to configure the stage2 page table and the attributes of memory
access. So we ensure that guests always access memory using cacheable
attributes and thus, the caches always be coherent.

So on CPUs that support S2FWB, we can safely reset the vcpu without a
heavy stage2 unmapping.

Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200415072835.1164-1-yuzenghui@huawei.com
2020-05-16 15:05:01 +01:00
Fuad Tabba
656012c731 KVM: Fix spelling in code comments
Fix spelling and typos (e.g., repeated words) in comments.

Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200401140310.29701-1-tabba@google.com
2020-05-16 15:05:01 +01:00
Marc Zyngier
9ed24f4b71 KVM: arm64: Move virt/kvm/arm to arch/arm64
Now that the 32bit KVM/arm host is a distant memory, let's move the
whole of the KVM/arm64 code into the arm64 tree.

As they said in the song: Welcome Home (Sanitarium).

Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200513104034.74741-1-maz@kernel.org
2020-05-16 15:03:59 +01:00
Renamed from virt/kvm/arm/arm.c (Browse further)