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Subject[PATCH 5/9] KVM: x86: Pass emulation type to can_emulate_instruction()
From
Pass the emulation type to kvm_x86_ops.can_emulate_insutrction() so that
a future commit can harden KVM's SEV support to WARN on emulation
scenarios that should never happen.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/include/asm/kvm_host.h | 3 ++-
arch/x86/kvm/svm/svm.c | 3 ++-
arch/x86/kvm/vmx/vmx.c | 7 ++++---
arch/x86/kvm/x86.c | 11 +++++++++--
4 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 682ad02a4e58..c890931c9c65 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1482,7 +1482,8 @@ struct kvm_x86_ops {

int (*get_msr_feature)(struct kvm_msr_entry *entry);

- bool (*can_emulate_instruction)(struct kvm_vcpu *vcpu, void *insn, int insn_len);
+ bool (*can_emulate_instruction)(struct kvm_vcpu *vcpu, int emul_type,
+ void *insn, int insn_len);

bool (*apic_init_signal_blocked)(struct kvm_vcpu *vcpu);
int (*enable_direct_tlbflush)(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index edea52be6c01..994224ae2731 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4257,7 +4257,8 @@ static void svm_enable_smi_window(struct kvm_vcpu *vcpu)
}
}

-static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, void *insn, int insn_len)
+static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
+ void *insn, int insn_len)
{
bool smep, smap, is_user;
unsigned long cr4;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index a02a28ce7cc3..4b4c1dfa6842 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1487,11 +1487,12 @@ static int vmx_rtit_ctl_check(struct kvm_vcpu *vcpu, u64 data)
return 0;
}

-static bool vmx_can_emulate_instruction(struct kvm_vcpu *vcpu, void *insn, int insn_len)
+static bool vmx_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
+ void *insn, int insn_len)
{
/*
* Emulation of instructions in SGX enclaves is impossible as RIP does
- * not point tthe failing instruction, and even if it did, the code
+ * not point at the failing instruction, and even if it did, the code
* stream is inaccessible. Inject #UD instead of exiting to userspace
* so that guest userspace can't DoS the guest simply by triggering
* emulation (enclaves are CPL3 only).
@@ -5397,7 +5398,7 @@ static int handle_ept_misconfig(struct kvm_vcpu *vcpu)
{
gpa_t gpa;

- if (!vmx_can_emulate_instruction(vcpu, NULL, 0))
+ if (!vmx_can_emulate_instruction(vcpu, EMULTYPE_PF, NULL, 0))
return 1;

/*
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 55518b7d3b96..2fa4687de8e4 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6810,6 +6810,13 @@ int kvm_write_guest_virt_system(struct kvm_vcpu *vcpu, gva_t addr, void *val,
}
EXPORT_SYMBOL_GPL(kvm_write_guest_virt_system);

+static int kvm_can_emulate_insn(struct kvm_vcpu *vcpu, int emul_type,
+ void *insn, int insn_len)
+{
+ return static_call(kvm_x86_can_emulate_instruction)(vcpu, emul_type,
+ insn, insn_len);
+}
+
int handle_ud(struct kvm_vcpu *vcpu)
{
static const char kvm_emulate_prefix[] = { __KVM_EMULATE_PREFIX };
@@ -6817,7 +6824,7 @@ int handle_ud(struct kvm_vcpu *vcpu)
char sig[5]; /* ud2; .ascii "kvm" */
struct x86_exception e;

- if (unlikely(!static_call(kvm_x86_can_emulate_instruction)(vcpu, NULL, 0)))
+ if (unlikely(!kvm_can_emulate_insn(vcpu, emul_type, NULL, 0)))
return 1;

if (force_emulation_prefix &&
@@ -8193,7 +8200,7 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
bool writeback = true;
bool write_fault_to_spt;

- if (unlikely(!static_call(kvm_x86_can_emulate_instruction)(vcpu, insn, insn_len)))
+ if (unlikely(!kvm_can_emulate_insn(vcpu, emulation_type, insn, insn_len)))
return 1;

vcpu->arch.l1tf_flush_l1d = true;
--
2.34.1.703.g22d0c6ccf7-goog
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