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linux-stable/arch/arm64/include/asm/kvm_hyp.h
Christoffer Dall 688c50aa72 KVM: arm/arm64: Move timer save/restore out of the hyp code 
As we are about to be lazy with saving and restoring the timer
registers, we prepare by moving all possible timer configuration logic
out of the hyp code.  All virtual timer registers can be programmed from
EL1 and since the arch timer is always a level triggered interrupt we
can safely do this with interrupts disabled in the host kernel on the
way to the guest without taking vtimer interrupts in the host kernel
(yet).

The downside is that the cntvoff register can only be programmed from
hyp mode, so we jump into hyp mode and back to program it.  This is also
safe, because the host kernel doesn't use the virtual timer in the KVM
code.  It may add a little performance performance penalty, but only
until following commits where we move this operation to vcpu load/put.

Signed-off-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-11-06 16:23:13 +01:00

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/*
* Copyright (C) 2015 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ARM64_KVM_HYP_H__
#define __ARM64_KVM_HYP_H__
#include <linux/compiler.h>
#include <linux/kvm_host.h>
#include <asm/kvm_mmu.h>
#include <asm/sysreg.h>
#define __hyp_text __section(.hyp.text) notrace
#define read_sysreg_elx(r,nvh,vh) \
({ \
u64 reg; \
asm volatile(ALTERNATIVE("mrs %0, " __stringify(r##nvh),\
"mrs_s %0, " __stringify(r##vh),\
ARM64_HAS_VIRT_HOST_EXTN) \
: "=r" (reg)); \
reg; \
})
#define write_sysreg_elx(v,r,nvh,vh) \
do { \
u64 __val = (u64)(v); \
asm volatile(ALTERNATIVE("msr " __stringify(r##nvh) ", %x0",\
"msr_s " __stringify(r##vh) ", %x0",\
ARM64_HAS_VIRT_HOST_EXTN) \
: : "rZ" (__val)); \
} while (0)
/*
* Unified accessors for registers that have a different encoding
* between VHE and non-VHE. They must be specified without their "ELx"
* encoding.
*/
#define read_sysreg_el2(r) \
({ \
u64 reg; \
asm volatile(ALTERNATIVE("mrs %0, " __stringify(r##_EL2),\
"mrs %0, " __stringify(r##_EL1),\
ARM64_HAS_VIRT_HOST_EXTN) \
: "=r" (reg)); \
reg; \
})
#define write_sysreg_el2(v,r) \
do { \
u64 __val = (u64)(v); \
asm volatile(ALTERNATIVE("msr " __stringify(r##_EL2) ", %x0",\
"msr " __stringify(r##_EL1) ", %x0",\
ARM64_HAS_VIRT_HOST_EXTN) \
: : "rZ" (__val)); \
} while (0)
#define read_sysreg_el0(r) read_sysreg_elx(r, _EL0, _EL02)
#define write_sysreg_el0(v,r) write_sysreg_elx(v, r, _EL0, _EL02)
#define read_sysreg_el1(r) read_sysreg_elx(r, _EL1, _EL12)
#define write_sysreg_el1(v,r) write_sysreg_elx(v, r, _EL1, _EL12)
/* The VHE specific system registers and their encoding */
#define sctlr_EL12 sys_reg(3, 5, 1, 0, 0)
#define cpacr_EL12 sys_reg(3, 5, 1, 0, 2)
#define ttbr0_EL12 sys_reg(3, 5, 2, 0, 0)
#define ttbr1_EL12 sys_reg(3, 5, 2, 0, 1)
#define tcr_EL12 sys_reg(3, 5, 2, 0, 2)
#define afsr0_EL12 sys_reg(3, 5, 5, 1, 0)
#define afsr1_EL12 sys_reg(3, 5, 5, 1, 1)
#define esr_EL12 sys_reg(3, 5, 5, 2, 0)
#define far_EL12 sys_reg(3, 5, 6, 0, 0)
#define mair_EL12 sys_reg(3, 5, 10, 2, 0)
#define amair_EL12 sys_reg(3, 5, 10, 3, 0)
#define vbar_EL12 sys_reg(3, 5, 12, 0, 0)
#define contextidr_EL12 sys_reg(3, 5, 13, 0, 1)
#define cntkctl_EL12 sys_reg(3, 5, 14, 1, 0)
#define cntp_tval_EL02 sys_reg(3, 5, 14, 2, 0)
#define cntp_ctl_EL02 sys_reg(3, 5, 14, 2, 1)
#define cntp_cval_EL02 sys_reg(3, 5, 14, 2, 2)
#define cntv_tval_EL02 sys_reg(3, 5, 14, 3, 0)
#define cntv_ctl_EL02 sys_reg(3, 5, 14, 3, 1)
#define cntv_cval_EL02 sys_reg(3, 5, 14, 3, 2)
#define spsr_EL12 sys_reg(3, 5, 4, 0, 0)
#define elr_EL12 sys_reg(3, 5, 4, 0, 1)
/**
* hyp_alternate_select - Generates patchable code sequences that are
* used to switch between two implementations of a function, depending
* on the availability of a feature.
*
* @fname: a symbol name that will be defined as a function returning a
* function pointer whose type will match @orig and @alt
* @orig: A pointer to the default function, as returned by @fname when
* @cond doesn't hold
* @alt: A pointer to the alternate function, as returned by @fname
* when @cond holds
* @cond: a CPU feature (as described in asm/cpufeature.h)
*/
#define hyp_alternate_select(fname, orig, alt, cond) \
typeof(orig) * __hyp_text fname(void) \
{ \
typeof(alt) *val = orig; \
asm volatile(ALTERNATIVE("nop \n", \
"mov %0, %1 \n", \
cond) \
: "+r" (val) : "r" (alt)); \
return val; \
}
void __vgic_v2_save_state(struct kvm_vcpu *vcpu);
void __vgic_v2_restore_state(struct kvm_vcpu *vcpu);
int __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu);
void __vgic_v3_save_state(struct kvm_vcpu *vcpu);
void __vgic_v3_restore_state(struct kvm_vcpu *vcpu);
int __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu);
void __timer_enable_traps(struct kvm_vcpu *vcpu);
void __timer_disable_traps(struct kvm_vcpu *vcpu);
void __sysreg_save_host_state(struct kvm_cpu_context *ctxt);
void __sysreg_restore_host_state(struct kvm_cpu_context *ctxt);
void __sysreg_save_guest_state(struct kvm_cpu_context *ctxt);
void __sysreg_restore_guest_state(struct kvm_cpu_context *ctxt);
void __sysreg32_save_state(struct kvm_vcpu *vcpu);
void __sysreg32_restore_state(struct kvm_vcpu *vcpu);
void __debug_save_state(struct kvm_vcpu *vcpu,
struct kvm_guest_debug_arch *dbg,
struct kvm_cpu_context *ctxt);
void __debug_restore_state(struct kvm_vcpu *vcpu,
struct kvm_guest_debug_arch *dbg,
struct kvm_cpu_context *ctxt);
void __debug_cond_save_host_state(struct kvm_vcpu *vcpu);
void __debug_cond_restore_host_state(struct kvm_vcpu *vcpu);
void __fpsimd_save_state(struct user_fpsimd_state *fp_regs);
void __fpsimd_restore_state(struct user_fpsimd_state *fp_regs);
bool __fpsimd_enabled(void);
u64 __guest_enter(struct kvm_vcpu *vcpu, struct kvm_cpu_context *host_ctxt);
void __noreturn __hyp_do_panic(unsigned long, ...);
#endif /* __ARM64_KVM_HYP_H__ */
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