[RFC PATCH 19/41] KVM: x86/pmu: Whitelist PMU MSRs for passthrough PMU

From: Xiong Zhang
Date: Fri Jan 26 2024 - 04:38:57 EST


From: Mingwei Zhang <mizhang@xxxxxxxxxx>

Whitelist PMU MSRs is_valid_passthrough_msr() to avoid warnings in kernel
message. In addition add comments in vmx_possible_passthrough_msrs() to
specify that interception of PMU MSRs are specially handled in
intel_passthrough_pmu_msrs().

Signed-off-by: Mingwei Zhang <mizhang@xxxxxxxxxx>
---
arch/x86/kvm/vmx/vmx.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 8ab266e1e2a7..349954f90fe9 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -158,7 +158,7 @@ module_param(allow_smaller_maxphyaddr, bool, S_IRUGO);

/*
* List of MSRs that can be directly passed to the guest.
- * In addition to these x2apic and PT MSRs are handled specially.
+ * In addition to these x2apic, PMU and PT MSRs are handled specially.
*/
static u32 vmx_possible_passthrough_msrs[MAX_POSSIBLE_PASSTHROUGH_MSRS] = {
MSR_IA32_SPEC_CTRL,
@@ -698,6 +698,15 @@ static bool is_valid_passthrough_msr(u32 msr)
case MSR_LBR_CORE_FROM ... MSR_LBR_CORE_FROM + 8:
case MSR_LBR_CORE_TO ... MSR_LBR_CORE_TO + 8:
/* LBR MSRs. These are handled in vmx_update_intercept_for_lbr_msrs() */
+ case MSR_ARCH_PERFMON_EVENTSEL0 ... MSR_ARCH_PERFMON_EVENTSEL0 + 7:
+ case MSR_IA32_PMC0 ... MSR_IA32_PMC0 + 7:
+ case MSR_IA32_PERFCTR0 ... MSR_IA32_PERFCTR0 + 7:
+ case MSR_CORE_PERF_FIXED_CTR_CTRL:
+ case MSR_CORE_PERF_FIXED_CTR0 ... MSR_CORE_PERF_FIXED_CTR0 + 2:
+ case MSR_CORE_PERF_GLOBAL_STATUS:
+ case MSR_CORE_PERF_GLOBAL_CTRL:
+ case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
+ /* PMU MSRs. These are handled in intel_passthrough_pmu_msrs() */
return true;
}

--
2.34.1