On Thu, Sep 29, 2022, Paolo Bonzini wrote:
> @@ -520,14 +505,14 @@ int emulator_leave_smm(struct x86_emulate_ctxt *ctxt)
> u64 smbase;
> int ret;
>
> - smbase = ctxt->ops->get_smbase(ctxt);
> + smbase = vcpu->arch.smbase;
>
> - ret = ctxt->ops->read_phys(ctxt, smbase + 0xfe00, buf, sizeof(buf));
> - if (ret != X86EMUL_CONTINUE)
> + ret = kvm_vcpu_read_guest(vcpu, smbase + 0xfe00, buf, sizeof(buf));
> + if (ret < 0)
> return X86EMUL_UNHANDLEABLE;
>
> - if ((ctxt->ops->get_hflags(ctxt) & X86EMUL_SMM_INSIDE_NMI_MASK) == 0)
> - ctxt->ops->set_nmi_mask(ctxt, false);
> + if ((vcpu->arch.hflags & HF_SMM_INSIDE_NMI_MASK) == 0)
> + static_call(kvm_x86_set_nmi_mask)(vcpu, false);
>
> kvm_smm_changed(vcpu, false);
>
> @@ -535,41 +520,41 @@ int emulator_leave_smm(struct x86_emulate_ctxt *ctxt)
> * Get back to real mode, to prepare a safe state in which to load
> * CR0/CR3/CR4/EFER. It's all a bit more complicated if the vCPU
> * supports long mode.
> - *
> - * The ctxt->ops callbacks will handle all side effects when writing
> - * writing MSRs and CRs, e.g. MMU context resets, CPUID
> - * runtime updates, etc.
> */
> - if (emulator_has_longmode(ctxt)) {
> - struct desc_struct cs_desc;
> +#ifdef CONFIG_X86_64
> + if (guest_cpuid_has(vcpu, X86_FEATURE_LM)) {
To fix the "unused 'efer'" issue and avoid multiple guest_cpuid_has() calls, this
as fixup? It's not like we care about the code footprint for 32-bit KVM if the
compiler isn't clever enough to optimize away the dead code.
---
arch/x86/kvm/smm.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kvm/smm.c b/arch/x86/kvm/smm.c
index 41ca128478fc..740fca1cf3a3 100644
--- a/arch/x86/kvm/smm.c
+++ b/arch/x86/kvm/smm.c
@@ -500,6 +500,8 @@ static int rsm_load_state_64(struct x86_emulate_ctxt *ctxt,
int emulator_leave_smm(struct x86_emulate_ctxt *ctxt)
{
struct kvm_vcpu *vcpu = ctxt->vcpu;
+ bool is_64bit_vcpu = IS_ENABLED(CONFIG_X86_64) &&
+ guest_cpuid_has(vcpu, X86_FEATURE_LM);
unsigned long cr0, cr4, efer;
char buf[512];
u64 smbase;
@@ -521,8 +523,7 @@ int emulator_leave_smm(struct x86_emulate_ctxt *ctxt)
* CR0/CR3/CR4/EFER. It's all a bit more complicated if the vCPU
* supports long mode.
*/
-#ifdef CONFIG_X86_64
- if (guest_cpuid_has(vcpu, X86_FEATURE_LM)) {
+ if (is_64bit_vcpu) {
struct kvm_segment cs_desc;
/* Zero CR4.PCIDE before CR0.PG. */
@@ -536,15 +537,13 @@ int emulator_leave_smm(struct x86_emulate_ctxt *ctxt)
cs_desc.s = cs_desc.g = cs_desc.present = 1;
kvm_set_segment(vcpu, &cs_desc, VCPU_SREG_CS);
}
-#endif
/* For the 64-bit case, this will clear EFER.LMA. */
cr0 = kvm_read_cr0(vcpu);
if (cr0 & X86_CR0_PE)
kvm_set_cr0(vcpu, cr0 & ~(X86_CR0_PG | X86_CR0_PE));
-#ifdef CONFIG_X86_64
- if (guest_cpuid_has(vcpu, X86_FEATURE_LM)) {
+ if (is_64bit_vcpu) {
/* Clear CR4.PAE before clearing EFER.LME. */
cr4 = kvm_read_cr4(vcpu);
if (cr4 & X86_CR4_PAE)
@@ -554,7 +553,6 @@ int emulator_leave_smm(struct x86_emulate_ctxt *ctxt)
efer = 0;
kvm_set_msr(vcpu, MSR_EFER, efer);
}
-#endif
/*
* Give leave_smm() a chance to make ISA-specific changes to the vCPU
@@ -565,7 +563,7 @@ int emulator_leave_smm(struct x86_emulate_ctxt *ctxt)
return X86EMUL_UNHANDLEABLE;
#ifdef CONFIG_X86_64
- if (guest_cpuid_has(vcpu, X86_FEATURE_LM))
+ if (is_64bit_vcpu)
return rsm_load_state_64(ctxt, buf);
else
#endif
base-commit: 8b86d27cc60a150252b04989de818ad4ec85f899
--
