linux/arch/x86/kvm/kvm_cache_regs.h
Sean Christopherson bd31fe495d KVM: VMX: Add proper cache tracking for CR0
Move CR0 caching into the standard register caching mechanism in order
to take advantage of the availability checks provided by regs_avail.
This avoids multiple VMREADs in the (uncommon) case where kvm_read_cr0()
is called multiple times in a single VM-Exit, and more importantly
eliminates a kvm_x86_ops hook, saves a retpoline on SVM when reading
CR0, and squashes the confusing naming discrepancy of "cache_reg" vs.
"decache_cr0_guest_bits".

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200502043234.12481-8-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-13 12:15:12 -04:00

183 lines
4.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef ASM_KVM_CACHE_REGS_H
#define ASM_KVM_CACHE_REGS_H
#include <linux/kvm_host.h>
#define KVM_POSSIBLE_CR0_GUEST_BITS X86_CR0_TS
#define KVM_POSSIBLE_CR4_GUEST_BITS \
(X86_CR4_PVI | X86_CR4_DE | X86_CR4_PCE | X86_CR4_OSFXSR \
| X86_CR4_OSXMMEXCPT | X86_CR4_LA57 | X86_CR4_PGE)
#define BUILD_KVM_GPR_ACCESSORS(lname, uname) \
static __always_inline unsigned long kvm_##lname##_read(struct kvm_vcpu *vcpu)\
{ \
return vcpu->arch.regs[VCPU_REGS_##uname]; \
} \
static __always_inline void kvm_##lname##_write(struct kvm_vcpu *vcpu, \
unsigned long val) \
{ \
vcpu->arch.regs[VCPU_REGS_##uname] = val; \
}
BUILD_KVM_GPR_ACCESSORS(rax, RAX)
BUILD_KVM_GPR_ACCESSORS(rbx, RBX)
BUILD_KVM_GPR_ACCESSORS(rcx, RCX)
BUILD_KVM_GPR_ACCESSORS(rdx, RDX)
BUILD_KVM_GPR_ACCESSORS(rbp, RBP)
BUILD_KVM_GPR_ACCESSORS(rsi, RSI)
BUILD_KVM_GPR_ACCESSORS(rdi, RDI)
#ifdef CONFIG_X86_64
BUILD_KVM_GPR_ACCESSORS(r8, R8)
BUILD_KVM_GPR_ACCESSORS(r9, R9)
BUILD_KVM_GPR_ACCESSORS(r10, R10)
BUILD_KVM_GPR_ACCESSORS(r11, R11)
BUILD_KVM_GPR_ACCESSORS(r12, R12)
BUILD_KVM_GPR_ACCESSORS(r13, R13)
BUILD_KVM_GPR_ACCESSORS(r14, R14)
BUILD_KVM_GPR_ACCESSORS(r15, R15)
#endif
static inline bool kvm_register_is_available(struct kvm_vcpu *vcpu,
enum kvm_reg reg)
{
return test_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
}
static inline bool kvm_register_is_dirty(struct kvm_vcpu *vcpu,
enum kvm_reg reg)
{
return test_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
}
static inline void kvm_register_mark_available(struct kvm_vcpu *vcpu,
enum kvm_reg reg)
{
__set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
}
static inline void kvm_register_mark_dirty(struct kvm_vcpu *vcpu,
enum kvm_reg reg)
{
__set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
__set_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
}
static inline unsigned long kvm_register_read(struct kvm_vcpu *vcpu, int reg)
{
if (WARN_ON_ONCE((unsigned int)reg >= NR_VCPU_REGS))
return 0;
if (!kvm_register_is_available(vcpu, reg))
kvm_x86_ops.cache_reg(vcpu, reg);
return vcpu->arch.regs[reg];
}
static inline void kvm_register_write(struct kvm_vcpu *vcpu, int reg,
unsigned long val)
{
if (WARN_ON_ONCE((unsigned int)reg >= NR_VCPU_REGS))
return;
vcpu->arch.regs[reg] = val;
kvm_register_mark_dirty(vcpu, reg);
}
static inline unsigned long kvm_rip_read(struct kvm_vcpu *vcpu)
{
return kvm_register_read(vcpu, VCPU_REGS_RIP);
}
static inline void kvm_rip_write(struct kvm_vcpu *vcpu, unsigned long val)
{
kvm_register_write(vcpu, VCPU_REGS_RIP, val);
}
static inline unsigned long kvm_rsp_read(struct kvm_vcpu *vcpu)
{
return kvm_register_read(vcpu, VCPU_REGS_RSP);
}
static inline void kvm_rsp_write(struct kvm_vcpu *vcpu, unsigned long val)
{
kvm_register_write(vcpu, VCPU_REGS_RSP, val);
}
static inline u64 kvm_pdptr_read(struct kvm_vcpu *vcpu, int index)
{
might_sleep(); /* on svm */
if (!kvm_register_is_available(vcpu, VCPU_EXREG_PDPTR))
kvm_x86_ops.cache_reg(vcpu, VCPU_EXREG_PDPTR);
return vcpu->arch.walk_mmu->pdptrs[index];
}
static inline ulong kvm_read_cr0_bits(struct kvm_vcpu *vcpu, ulong mask)
{
ulong tmask = mask & KVM_POSSIBLE_CR0_GUEST_BITS;
if ((tmask & vcpu->arch.cr0_guest_owned_bits) &&
!kvm_register_is_available(vcpu, VCPU_EXREG_CR0))
kvm_x86_ops.cache_reg(vcpu, VCPU_EXREG_CR0);
return vcpu->arch.cr0 & mask;
}
static inline ulong kvm_read_cr0(struct kvm_vcpu *vcpu)
{
return kvm_read_cr0_bits(vcpu, ~0UL);
}
static inline ulong kvm_read_cr4_bits(struct kvm_vcpu *vcpu, ulong mask)
{
ulong tmask = mask & KVM_POSSIBLE_CR4_GUEST_BITS;
if ((tmask & vcpu->arch.cr4_guest_owned_bits) &&
!kvm_register_is_available(vcpu, VCPU_EXREG_CR4))
kvm_x86_ops.cache_reg(vcpu, VCPU_EXREG_CR4);
return vcpu->arch.cr4 & mask;
}
static inline ulong kvm_read_cr3(struct kvm_vcpu *vcpu)
{
if (!kvm_register_is_available(vcpu, VCPU_EXREG_CR3))
kvm_x86_ops.cache_reg(vcpu, VCPU_EXREG_CR3);
return vcpu->arch.cr3;
}
static inline ulong kvm_read_cr4(struct kvm_vcpu *vcpu)
{
return kvm_read_cr4_bits(vcpu, ~0UL);
}
static inline u64 kvm_read_edx_eax(struct kvm_vcpu *vcpu)
{
return (kvm_rax_read(vcpu) & -1u)
| ((u64)(kvm_rdx_read(vcpu) & -1u) << 32);
}
static inline void enter_guest_mode(struct kvm_vcpu *vcpu)
{
vcpu->arch.hflags |= HF_GUEST_MASK;
}
static inline void leave_guest_mode(struct kvm_vcpu *vcpu)
{
vcpu->arch.hflags &= ~HF_GUEST_MASK;
if (vcpu->arch.load_eoi_exitmap_pending) {
vcpu->arch.load_eoi_exitmap_pending = false;
kvm_make_request(KVM_REQ_LOAD_EOI_EXITMAP, vcpu);
}
}
static inline bool is_guest_mode(struct kvm_vcpu *vcpu)
{
return vcpu->arch.hflags & HF_GUEST_MASK;
}
static inline bool is_smm(struct kvm_vcpu *vcpu)
{
return vcpu->arch.hflags & HF_SMM_MASK;
}
#endif