[PATCH 1/6] KVM: x86: add an emulation_reason to x86_emulate_instruction()

From: David Edmondson
Date: Mon Apr 12 2021 - 09:09:56 EST


From: Joao Martins <joao.m.martins@xxxxxxxxxx>

Emulation can happen for a variety of reasons, yet on error we have no
idea exactly what triggered it. Expand x86_emulate_instruction() to
carry an @emulation_reason argument.

Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
Signed-off-by: David Edmondson <david.edmondson@xxxxxxxxxx>
---
arch/x86/kvm/mmu/mmu.c | 4 ++--
arch/x86/kvm/x86.c | 7 ++++---
arch/x86/kvm/x86.h | 3 ++-
3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 951dae4e7175..515ff790b7c5 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5056,8 +5056,8 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code,
if (!mmio_info_in_cache(vcpu, cr2_or_gpa, direct) && !is_guest_mode(vcpu))
emulation_type |= EMULTYPE_ALLOW_RETRY_PF;
emulate:
- return x86_emulate_instruction(vcpu, cr2_or_gpa, emulation_type, insn,
- insn_len);
+ return x86_emulate_instruction(vcpu, cr2_or_gpa, emulation_type, 0,
+ insn, insn_len);
}
EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index eca63625aee4..87e76f3aee64 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7445,7 +7445,8 @@ int x86_decode_emulated_instruction(struct kvm_vcpu *vcpu, int emulation_type,
EXPORT_SYMBOL_GPL(x86_decode_emulated_instruction);

int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
- int emulation_type, void *insn, int insn_len)
+ int emulation_type, int emulation_reason,
+ void *insn, int insn_len)
{
int r;
struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt;
@@ -7604,14 +7605,14 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,

int kvm_emulate_instruction(struct kvm_vcpu *vcpu, int emulation_type)
{
- return x86_emulate_instruction(vcpu, 0, emulation_type, NULL, 0);
+ return x86_emulate_instruction(vcpu, 0, emulation_type, 0, NULL, 0);
}
EXPORT_SYMBOL_GPL(kvm_emulate_instruction);

int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu,
void *insn, int insn_len)
{
- return x86_emulate_instruction(vcpu, 0, 0, insn, insn_len);
+ return x86_emulate_instruction(vcpu, 0, 0, 0, insn, insn_len);
}
EXPORT_SYMBOL_GPL(kvm_emulate_instruction_from_buffer);

diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 9035e34aa156..5686436c99da 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -276,7 +276,8 @@ void kvm_fixup_and_inject_pf_error(struct kvm_vcpu *vcpu, gva_t gva, u16 error_c
int x86_decode_emulated_instruction(struct kvm_vcpu *vcpu, int emulation_type,
void *insn, int insn_len);
int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
- int emulation_type, void *insn, int insn_len);
+ int emulation_type, int emulation_reason,
+ void *insn, int insn_len);
fastpath_t handle_fastpath_set_msr_irqoff(struct kvm_vcpu *vcpu);

extern u64 host_xcr0;
--
2.30.2