Commit 3b36160d authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: nSVM: Disable PMU MSR interception as appropriate while running L2 



Add MSRs that might be passed through to L1 when running with a mediated
PMU to the nested SVM's set of to-be-merged MSR indices, i.e. disable
interception of PMU MSRs when running L2 if both KVM (L0) and L1 disable
interception.  There is no need for KVM to interpose on such MSR accesses,
e.g. if L1 exposes a mediated PMU (or equivalent) to L2.

Tested-by: default avatarXudong Hao <xudong.hao@intel.com>
Tested-by: default avatarManali Shukla <manali.shukla@amd.com>
Link: https://patch.msgid.link/20251206001720.468579-33-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 88ebc2a3

arch/x86/kvm/svm/nested.c

+17 −1
Original line number Diff line number Diff line
@@ -194,7 +194,7 @@ void recalc_intercepts(struct vcpu_svm *svm) 
 * Hardcode the capacity of the array based on the maximum number of _offsets_.

 * MSRs are batched together, so there are fewer offsets than MSRs.

 */

static int nested_svm_msrpm_merge_offsets[7] __ro_after_init;

static int nested_svm_msrpm_merge_offsets[10] __ro_after_init;

static int nested_svm_nr_msrpm_merge_offsets __ro_after_init;

typedef unsigned long nsvm_msrpm_merge_t;
@@ -222,6 +222,22 @@ int __init nested_svm_init_msrpm_merge_offsets(void) 
		MSR_IA32_LASTBRANCHTOIP,

		MSR_IA32_LASTINTFROMIP,

		MSR_IA32_LASTINTTOIP,



		MSR_K7_PERFCTR0,

		MSR_K7_PERFCTR1,

		MSR_K7_PERFCTR2,

		MSR_K7_PERFCTR3,

		MSR_F15H_PERF_CTR0,

		MSR_F15H_PERF_CTR1,

		MSR_F15H_PERF_CTR2,

		MSR_F15H_PERF_CTR3,

		MSR_F15H_PERF_CTR4,

		MSR_F15H_PERF_CTR5,



		MSR_AMD64_PERF_CNTR_GLOBAL_CTL,

		MSR_AMD64_PERF_CNTR_GLOBAL_STATUS,

		MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR,

		MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_SET,

	};

	int i, j;