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Diffstat (limited to 'arch/x86/kvm/svm.c')
-rw-r--r--arch/x86/kvm/svm.c97
1 files changed, 62 insertions, 35 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index b58787daf9f8..26110c202b19 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -49,7 +49,7 @@
#include <asm/debugreg.h>
#include <asm/kvm_para.h>
#include <asm/irq_remapping.h>
-#include <asm/nospec-branch.h>
+#include <asm/spec-ctrl.h>
#include <asm/virtext.h>
#include "trace.h"
@@ -213,6 +213,12 @@ struct vcpu_svm {
} host;
u64 spec_ctrl;
+ /*
+ * Contains guest-controlled bits of VIRT_SPEC_CTRL, which will be
+ * translated into the appropriate L2_CFG bits on the host to
+ * perform speculative control.
+ */
+ u64 virt_spec_ctrl;
u32 *msrpm;
@@ -1423,12 +1429,23 @@ static void init_sys_seg(struct vmcb_seg *seg, uint32_t type)
seg->base = 0;
}
+static u64 svm_read_l1_tsc_offset(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_svm *svm = to_svm(vcpu);
+
+ if (is_guest_mode(vcpu))
+ return svm->nested.hsave->control.tsc_offset;
+
+ return vcpu->arch.tsc_offset;
+}
+
static void svm_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset)
{
struct vcpu_svm *svm = to_svm(vcpu);
u64 g_tsc_offset = 0;
if (is_guest_mode(vcpu)) {
+ /* Write L1's TSC offset. */
g_tsc_offset = svm->vmcb->control.tsc_offset -
svm->nested.hsave->control.tsc_offset;
svm->nested.hsave->control.tsc_offset = offset;
@@ -2049,6 +2066,7 @@ static void svm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
vcpu->arch.microcode_version = 0x01000065;
svm->spec_ctrl = 0;
+ svm->virt_spec_ctrl = 0;
if (!init_event) {
svm->vcpu.arch.apic_base = APIC_DEFAULT_PHYS_BASE |
@@ -3322,6 +3340,7 @@ static int nested_svm_vmexit(struct vcpu_svm *svm)
/* Restore the original control entries */
copy_vmcb_control_area(vmcb, hsave);
+ svm->vcpu.arch.tsc_offset = svm->vmcb->control.tsc_offset;
kvm_clear_exception_queue(&svm->vcpu);
kvm_clear_interrupt_queue(&svm->vcpu);
@@ -3482,10 +3501,12 @@ static void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
/* We don't want to see VMMCALLs from a nested guest */
clr_intercept(svm, INTERCEPT_VMMCALL);
+ svm->vcpu.arch.tsc_offset += nested_vmcb->control.tsc_offset;
+ svm->vmcb->control.tsc_offset = svm->vcpu.arch.tsc_offset;
+
svm->vmcb->control.virt_ext = nested_vmcb->control.virt_ext;
svm->vmcb->control.int_vector = nested_vmcb->control.int_vector;
svm->vmcb->control.int_state = nested_vmcb->control.int_state;
- svm->vmcb->control.tsc_offset += nested_vmcb->control.tsc_offset;
svm->vmcb->control.event_inj = nested_vmcb->control.event_inj;
svm->vmcb->control.event_inj_err = nested_vmcb->control.event_inj_err;
@@ -4035,12 +4056,6 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
struct vcpu_svm *svm = to_svm(vcpu);
switch (msr_info->index) {
- case MSR_IA32_TSC: {
- msr_info->data = svm->vmcb->control.tsc_offset +
- kvm_scale_tsc(vcpu, rdtsc());
-
- break;
- }
case MSR_STAR:
msr_info->data = svm->vmcb->save.star;
break;
@@ -4100,11 +4115,18 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
break;
case MSR_IA32_SPEC_CTRL:
if (!msr_info->host_initiated &&
- !guest_cpuid_has(vcpu, X86_FEATURE_IBRS))
+ !guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBRS))
return 1;
msr_info->data = svm->spec_ctrl;
break;
+ case MSR_AMD64_VIRT_SPEC_CTRL:
+ if (!msr_info->host_initiated &&
+ !guest_cpuid_has(vcpu, X86_FEATURE_VIRT_SSBD))
+ return 1;
+
+ msr_info->data = svm->virt_spec_ctrl;
+ break;
case MSR_F15H_IC_CFG: {
int family, model;
@@ -4193,12 +4215,9 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
svm->vmcb->save.g_pat = data;
mark_dirty(svm->vmcb, VMCB_NPT);
break;
- case MSR_IA32_TSC:
- kvm_write_tsc(vcpu, msr);
- break;
case MSR_IA32_SPEC_CTRL:
if (!msr->host_initiated &&
- !guest_cpuid_has(vcpu, X86_FEATURE_IBRS))
+ !guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBRS))
return 1;
/* The STIBP bit doesn't fault even if it's not advertised */
@@ -4225,7 +4244,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
break;
case MSR_IA32_PRED_CMD:
if (!msr->host_initiated &&
- !guest_cpuid_has(vcpu, X86_FEATURE_IBPB))
+ !guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBPB))
return 1;
if (data & ~PRED_CMD_IBPB)
@@ -4239,6 +4258,16 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
break;
set_msr_interception(svm->msrpm, MSR_IA32_PRED_CMD, 0, 1);
break;
+ case MSR_AMD64_VIRT_SPEC_CTRL:
+ if (!msr->host_initiated &&
+ !guest_cpuid_has(vcpu, X86_FEATURE_VIRT_SSBD))
+ return 1;
+
+ if (data & ~SPEC_CTRL_SSBD)
+ return 1;
+
+ svm->virt_spec_ctrl = data;
+ break;
case MSR_STAR:
svm->vmcb->save.star = data;
break;
@@ -5265,9 +5294,8 @@ static int svm_update_pi_irte(struct kvm *kvm, unsigned int host_irq,
}
if (!ret && svm) {
- trace_kvm_pi_irte_update(svm->vcpu.vcpu_id,
- host_irq, e->gsi,
- vcpu_info.vector,
+ trace_kvm_pi_irte_update(host_irq, svm->vcpu.vcpu_id,
+ e->gsi, vcpu_info.vector,
vcpu_info.pi_desc_addr, set);
}
@@ -5553,8 +5581,7 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu)
* is no need to worry about the conditional branch over the wrmsr
* being speculatively taken.
*/
- if (svm->spec_ctrl)
- native_wrmsrl(MSR_IA32_SPEC_CTRL, svm->spec_ctrl);
+ x86_spec_ctrl_set_guest(svm->spec_ctrl, svm->virt_spec_ctrl);
asm volatile (
"push %%" _ASM_BP "; \n\t"
@@ -5648,6 +5675,18 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu)
#endif
);
+ /* Eliminate branch target predictions from guest mode */
+ vmexit_fill_RSB();
+
+#ifdef CONFIG_X86_64
+ wrmsrl(MSR_GS_BASE, svm->host.gs_base);
+#else
+ loadsegment(fs, svm->host.fs);
+#ifndef CONFIG_X86_32_LAZY_GS
+ loadsegment(gs, svm->host.gs);
+#endif
+#endif
+
/*
* We do not use IBRS in the kernel. If this vCPU has used the
* SPEC_CTRL MSR it may have left it on; save the value and
@@ -5666,20 +5705,7 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu)
if (unlikely(!msr_write_intercepted(vcpu, MSR_IA32_SPEC_CTRL)))
svm->spec_ctrl = native_read_msr(MSR_IA32_SPEC_CTRL);
- if (svm->spec_ctrl)
- native_wrmsrl(MSR_IA32_SPEC_CTRL, 0);
-
- /* Eliminate branch target predictions from guest mode */
- vmexit_fill_RSB();
-
-#ifdef CONFIG_X86_64
- wrmsrl(MSR_GS_BASE, svm->host.gs_base);
-#else
- loadsegment(fs, svm->host.fs);
-#ifndef CONFIG_X86_32_LAZY_GS
- loadsegment(gs, svm->host.gs);
-#endif
-#endif
+ x86_spec_ctrl_restore_host(svm->spec_ctrl, svm->virt_spec_ctrl);
reload_tss(vcpu);
@@ -5782,7 +5808,7 @@ static bool svm_cpu_has_accelerated_tpr(void)
return false;
}
-static bool svm_has_high_real_mode_segbase(void)
+static bool svm_has_emulated_msr(int index)
{
return true;
}
@@ -7008,7 +7034,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
.hardware_enable = svm_hardware_enable,
.hardware_disable = svm_hardware_disable,
.cpu_has_accelerated_tpr = svm_cpu_has_accelerated_tpr,
- .cpu_has_high_real_mode_segbase = svm_has_high_real_mode_segbase,
+ .has_emulated_msr = svm_has_emulated_msr,
.vcpu_create = svm_create_vcpu,
.vcpu_free = svm_free_vcpu,
@@ -7102,6 +7128,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
.has_wbinvd_exit = svm_has_wbinvd_exit,
+ .read_l1_tsc_offset = svm_read_l1_tsc_offset,
.write_tsc_offset = svm_write_tsc_offset,
.set_tdp_cr3 = set_tdp_cr3,
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.