[PATCH v2 43/54] KVM: x86/pmu: Update pmc_{read,write}_counter() to disconnect perf API

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Update pmc_{read,write}_counter() to disconnect perf API because
passthrough PMU does not use host PMU on backend. Because of that
pmc->counter contains directly the actual value of the guest VM when set by
the host (VMM) side.

Signed-off-by: Mingwei Zhang <mizhang@xxxxxxxxxx>
Signed-off-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
---
 arch/x86/kvm/pmu.c | 5 +++++
 arch/x86/kvm/pmu.h | 4 ++++
 2 files changed, 9 insertions(+)

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 06e70f74559d..12330d3f92f4 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -322,6 +322,11 @@ static void pmc_update_sample_period(struct kvm_pmc *pmc)
 
 void pmc_write_counter(struct kvm_pmc *pmc, u64 val)
 {
+	if (pmc_to_pmu(pmc)->passthrough) {
+		pmc->counter = val;
+		return;
+	}
+
 	/*
 	 * Drop any unconsumed accumulated counts, the WRMSR is a write, not a
 	 * read-modify-write.  Adjust the counter value so that its value is
diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
index 78a7f0c5f3ba..7e006cb61296 100644
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -116,6 +116,10 @@ static inline u64 pmc_read_counter(struct kvm_pmc *pmc)
 {
 	u64 counter, enabled, running;
 
+	counter = pmc->counter;
+	if (pmc_to_pmu(pmc)->passthrough)
+		return counter & pmc_bitmask(pmc);
+
 	counter = pmc->counter + pmc->emulated_counter;
 
 	if (pmc->perf_event && !pmc->is_paused)
-- 
2.45.0.rc1.225.g2a3ae87e7f-goog





[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux