[PATCH 15/23] KVM: x86: Move XSETBV emulation to common code

From: Paolo Bonzini
Date: Tue Mar 02 2021 - 17:38:03 EST


From: Sean Christopherson <seanjc@xxxxxxxxxx>

Move the entirety of XSETBV emulation to x86.c, and assign the
function directly to both VMX's and SVM's exit handlers, i.e. drop the
unnecessary trampolines.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Message-Id: <20210205005750.3841462-6-seanjc@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 2 +-
arch/x86/kvm/svm/svm.c | 11 +----------
arch/x86/kvm/vmx/vmx.c | 11 +----------
arch/x86/kvm/x86.c | 13 ++++++++-----
4 files changed, 11 insertions(+), 26 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 85ccbd4b7c52..b396e854c7db 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1542,7 +1542,7 @@ void kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val);
unsigned long kvm_get_cr8(struct kvm_vcpu *vcpu);
void kvm_lmsw(struct kvm_vcpu *vcpu, unsigned long msw);
void kvm_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l);
-int kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr);
+int kvm_emulate_xsetbv(struct kvm_vcpu *vcpu);

int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr);
int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 5815fedf978e..fcea45f40d76 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2346,15 +2346,6 @@ static int wbinvd_interception(struct kvm_vcpu *vcpu)
return kvm_emulate_wbinvd(vcpu);
}

-static int xsetbv_interception(struct kvm_vcpu *vcpu)
-{
- u64 new_bv = kvm_read_edx_eax(vcpu);
- u32 index = kvm_rcx_read(vcpu);
-
- int err = kvm_set_xcr(vcpu, index, new_bv);
- return kvm_complete_insn_gp(vcpu, err);
-}
-
static int rdpru_interception(struct kvm_vcpu *vcpu)
{
kvm_queue_exception(vcpu, UD_VECTOR);
@@ -3156,7 +3147,7 @@ static int (*const svm_exit_handlers[])(struct kvm_vcpu *vcpu) = {
[SVM_EXIT_WBINVD] = wbinvd_interception,
[SVM_EXIT_MONITOR] = monitor_interception,
[SVM_EXIT_MWAIT] = mwait_interception,
- [SVM_EXIT_XSETBV] = xsetbv_interception,
+ [SVM_EXIT_XSETBV] = kvm_emulate_xsetbv,
[SVM_EXIT_RDPRU] = rdpru_interception,
[SVM_EXIT_EFER_WRITE_TRAP] = efer_trap,
[SVM_EXIT_CR0_WRITE_TRAP] = cr_trap,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 50810d471462..0df836897447 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5216,15 +5216,6 @@ static int handle_wbinvd(struct kvm_vcpu *vcpu)
return kvm_emulate_wbinvd(vcpu);
}

-static int handle_xsetbv(struct kvm_vcpu *vcpu)
-{
- u64 new_bv = kvm_read_edx_eax(vcpu);
- u32 index = kvm_rcx_read(vcpu);
-
- int err = kvm_set_xcr(vcpu, index, new_bv);
- return kvm_complete_insn_gp(vcpu, err);
-}
-
static int handle_apic_access(struct kvm_vcpu *vcpu)
{
if (likely(fasteoi)) {
@@ -5686,7 +5677,7 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
[EXIT_REASON_APIC_WRITE] = handle_apic_write,
[EXIT_REASON_EOI_INDUCED] = handle_apic_eoi_induced,
[EXIT_REASON_WBINVD] = handle_wbinvd,
- [EXIT_REASON_XSETBV] = handle_xsetbv,
+ [EXIT_REASON_XSETBV] = kvm_emulate_xsetbv,
[EXIT_REASON_TASK_SWITCH] = handle_task_switch,
[EXIT_REASON_MCE_DURING_VMENTRY] = handle_machine_check,
[EXIT_REASON_GDTR_IDTR] = handle_desc,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1d2bc89431a2..8dc69ff3d205 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -984,14 +984,17 @@ static int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
return 0;
}

-int kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
+int kvm_emulate_xsetbv(struct kvm_vcpu *vcpu)
{
- if (static_call(kvm_x86_get_cpl)(vcpu) == 0)
- return __kvm_set_xcr(vcpu, index, xcr);
+ if (static_call(kvm_x86_get_cpl)(vcpu) != 0 ||
+ __kvm_set_xcr(vcpu, kvm_rcx_read(vcpu), kvm_read_edx_eax(vcpu))) {
+ kvm_inject_gp(vcpu, 0);
+ return 1;
+ }

- return 1;
+ return kvm_skip_emulated_instruction(vcpu);
}
-EXPORT_SYMBOL_GPL(kvm_set_xcr);
+EXPORT_SYMBOL_GPL(kvm_emulate_xsetbv);

bool kvm_is_valid_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
{
--
2.26.2