If the hardware can handle accesses, we should allow it to do so. This
way we can expose EFRO to HVM guests, and "all" that's left for exposing
APERF/MPERF is to figure out how to handle writes to these MSRs. (Note
that the leaf 6 guest CPUID checks will evaluate to false for now, as
recalculate_misc() zaps the entire leaf for now.)
For TSC the intercepts are made mirror the RDTSC ones.
Signed-off-by: Jan Beulich <jbeul...@suse.com>
---
v4: Make TSC intercepts mirror RDTSC ones. Re-base.
v3: New.
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -595,6 +595,7 @@ static void svm_cpuid_policy_changed(str
struct vmcb_struct *vmcb = svm->vmcb;
const struct cpuid_policy *cp = v->domain->arch.cpuid;
u32 bitmap = vmcb_get_exception_intercepts(vmcb);
+ unsigned int mode;
if ( opt_hvm_fep ||
(v->domain->arch.cpuid->x86_vendor != boot_cpu_data.x86_vendor) )
@@ -607,6 +608,17 @@ static void svm_cpuid_policy_changed(str
/* Give access to MSR_PRED_CMD if the guest has been told about it. */
svm_intercept_msr(v, MSR_PRED_CMD,
cp->extd.ibpb ? MSR_INTERCEPT_NONE : MSR_INTERCEPT_RW);
+
+ /* Allow direct reads from APERF/MPERF if permitted by the policy. */
+ mode = cp->basic.raw[6].c & CPUID6_ECX_APERFMPERF_CAPABILITY
+ ? MSR_INTERCEPT_WRITE : MSR_INTERCEPT_RW;
+ svm_intercept_msr(v, MSR_IA32_APERF, mode);
+ svm_intercept_msr(v, MSR_IA32_MPERF, mode);
+
+ /* Allow direct access to their r/o counterparts if permitted. */
+ mode = cp->extd.efro ? MSR_INTERCEPT_NONE : MSR_INTERCEPT_RW;
+ svm_intercept_msr(v, MSR_APERF_RD_ONLY, mode);
+ svm_intercept_msr(v, MSR_MPERF_RD_ONLY, mode);
}
void svm_sync_vmcb(struct vcpu *v, enum vmcb_sync_state new_state)
@@ -860,7 +872,10 @@ static void svm_set_rdtsc_exiting(struct
{
general1_intercepts |= GENERAL1_INTERCEPT_RDTSC;
general2_intercepts |= GENERAL2_INTERCEPT_RDTSCP;
+ svm_enable_intercept_for_msr(v, MSR_IA32_TSC);
}
+ else
+ svm_intercept_msr(v, MSR_IA32_TSC, MSR_INTERCEPT_WRITE);
vmcb_set_general1_intercepts(vmcb, general1_intercepts);
vmcb_set_general2_intercepts(vmcb, general2_intercepts);
--- a/xen/arch/x86/hvm/svm/vmcb.c
+++ b/xen/arch/x86/hvm/svm/vmcb.c
@@ -108,6 +108,7 @@ static int construct_vmcb(struct vcpu *v
{
vmcb->_general1_intercepts |= GENERAL1_INTERCEPT_RDTSC;
vmcb->_general2_intercepts |= GENERAL2_INTERCEPT_RDTSCP;
+ svm_intercept_msr(v, MSR_IA32_TSC, MSR_INTERCEPT_WRITE);
}
/* Guest segment limits. */
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -1140,8 +1140,13 @@ static int construct_vmcs(struct vcpu *v
vmx_clear_msr_intercept(v, MSR_IA32_SYSENTER_CS, VMX_MSR_RW);
vmx_clear_msr_intercept(v, MSR_IA32_SYSENTER_ESP, VMX_MSR_RW);
vmx_clear_msr_intercept(v, MSR_IA32_SYSENTER_EIP, VMX_MSR_RW);
+
+ if ( !(v->arch.hvm.vmx.exec_control & CPU_BASED_RDTSC_EXITING) )
+ vmx_clear_msr_intercept(v, MSR_IA32_TSC, VMX_MSR_R);
+
if ( paging_mode_hap(d) && (!is_iommu_enabled(d) || iommu_snoop) )
vmx_clear_msr_intercept(v, MSR_IA32_CR_PAT, VMX_MSR_RW);
+
if ( (vmexit_ctl & VM_EXIT_CLEAR_BNDCFGS) &&
(vmentry_ctl & VM_ENTRY_LOAD_BNDCFGS) )
vmx_clear_msr_intercept(v, MSR_IA32_BNDCFGS, VMX_MSR_RW);
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -584,6 +584,18 @@ static void vmx_cpuid_policy_changed(str
vmx_clear_msr_intercept(v, MSR_FLUSH_CMD, VMX_MSR_RW);
else
vmx_set_msr_intercept(v, MSR_FLUSH_CMD, VMX_MSR_RW);
+
+ /* Allow direct reads from APERF/MPERF if permitted by the policy. */
+ if ( cp->basic.raw[6].c & CPUID6_ECX_APERFMPERF_CAPABILITY )
+ {
+ vmx_clear_msr_intercept(v, MSR_IA32_APERF, VMX_MSR_R);
+ vmx_clear_msr_intercept(v, MSR_IA32_MPERF, VMX_MSR_R);
+ }
+ else
+ {
+ vmx_set_msr_intercept(v, MSR_IA32_APERF, VMX_MSR_R);
+ vmx_set_msr_intercept(v, MSR_IA32_MPERF, VMX_MSR_R);
+ }
}
int vmx_guest_x86_mode(struct vcpu *v)
@@ -1249,7 +1261,12 @@ static void vmx_set_rdtsc_exiting(struct
vmx_vmcs_enter(v);
v->arch.hvm.vmx.exec_control &= ~CPU_BASED_RDTSC_EXITING;
if ( enable )
+ {
v->arch.hvm.vmx.exec_control |= CPU_BASED_RDTSC_EXITING;
+ vmx_set_msr_intercept(v, MSR_IA32_TSC, VMX_MSR_R);
+ }
+ else
+ vmx_clear_msr_intercept(v, MSR_IA32_TSC, VMX_MSR_R);
vmx_update_cpu_exec_control(v);
vmx_vmcs_exit(v);
}
--- a/xen/include/public/arch-x86/cpufeatureset.h
+++ b/xen/include/public/arch-x86/cpufeatureset.h
@@ -242,7 +242,7 @@ XEN_CPUFEATURE(MOVDIR64B, 6*32+28) /
/* AMD-defined CPU features, CPUID level 0x80000007.edx, word 7 */
XEN_CPUFEATURE(ITSC, 7*32+ 8) /* Invariant TSC */
-XEN_CPUFEATURE(EFRO, 7*32+10) /* APERF/MPERF Read Only interface */
+XEN_CPUFEATURE(EFRO, 7*32+10) /*S APERF/MPERF Read Only interface */
/* AMD-defined CPU features, CPUID level 0x80000008.ebx, word 8 */
XEN_CPUFEATURE(CLZERO, 8*32+ 0) /*A CLZERO instruction */
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