KVM: x86: Add support for VMware backdoor Pseudo-PMCs

VMware exposes the following Pseudo PMCs:
0x10000: Physical host TSC
0x10001: Elapsed real time in ns
0x10002: Elapsed apparent time in ns

For more info refer to:
https://www.vmware.com/files/pdf/techpaper/Timekeeping-In-VirtualMachines.pdf

VMware allows access to these Pseduo-PMCs even when read via RDPMC
in Ring3 and CR4.PCE=0. Therefore, commit modifies x86 emulator
to allow access to these PMCs in this situation. In addition,
emulation of these PMCs were added to kvm_pmu_rdpmc().

Signed-off-by: Arbel Moshe <arbel.moshe@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Arbel Moshe
2018-03-12 13:12:53 +02:00
committed by Paolo Bonzini
parent 9718420e9f
commit 2d7921c499
4 changed files with 75 additions and 17 deletions

View File

@@ -9,6 +9,10 @@
/* retrieve the 4 bits for EN and PMI out of IA32_FIXED_CTR_CTRL */
#define fixed_ctrl_field(ctrl_reg, idx) (((ctrl_reg) >> ((idx)*4)) & 0xf)
#define VMWARE_BACKDOOR_PMC_HOST_TSC 0x10000
#define VMWARE_BACKDOOR_PMC_REAL_TIME 0x10001
#define VMWARE_BACKDOOR_PMC_APPARENT_TIME 0x10002
struct kvm_event_hw_type_mapping {
u8 eventsel;
u8 unit_mask;
@@ -114,6 +118,8 @@ void kvm_pmu_reset(struct kvm_vcpu *vcpu);
void kvm_pmu_init(struct kvm_vcpu *vcpu);
void kvm_pmu_destroy(struct kvm_vcpu *vcpu);
bool is_vmware_backdoor_pmc(u32 pmc_idx);
extern struct kvm_pmu_ops intel_pmu_ops;
extern struct kvm_pmu_ops amd_pmu_ops;
#endif /* __KVM_X86_PMU_H */