On 10/03/2011 03:49 PM, Gleb Natapov wrote:
Support guest/host-only profiling by switch perf msrs on
a guest entry if needed.
@@ -6052,6 +6056,26 @@ static void vmx_cancel_injection(struct kvm_vcpu *vcpu)
vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, 0);
}
+static void atomic_switch_perf_msrs(struct vcpu_vmx *vmx)
+{
+#ifdef CONFIG_PERF_EVENTS
No need for #ifdef (if you also define perf_guest_get_msrs() when
!CONFIG_PERF_EVENTS).
+ int i;
+
+ if (!cpu_has_arch_perfmon || vmx->perf_msrs_cnt<= 0)
+ return;
Why the first check?
+
+ perf_guest_get_msrs(vmx->perf_msrs_cnt, vmx->perf_msrs);
+ for (i = 0; i< vmx->perf_msrs_cnt; i++) {
+ struct perf_guest_switch_msr *msr =&vmx->perf_msrs[i];
+ if (msr->host == msr->guest)
+ clear_atomic_switch_msr(vmx, msr->msr);
+ else
+ add_atomic_switch_msr(vmx, msr->msr, msr->guest,
+ msr->host);
This generates a lot of VMWRITEs even if nothing changes, just to re-set
bits in the VMCS to their existing values. Need to add something like this:
if (loaded_vmcs->msr[i].host == msr->host
&& loaded_vmcs->msr[i].guest == msr->guest)
continue;
btw, shouldn't the msr autoload list be part of loaded_vmcs as well?
+ }
+#endif
+}
+
#ifdef CONFIG_X86_64
#define R "r"
#define Q "q"
@@ -6101,6 +6125,8 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
if (vcpu->guest_debug& KVM_GUESTDBG_SINGLESTEP)
vmx_set_interrupt_shadow(vcpu, 0);
+ atomic_switch_perf_msrs(vmx);
+
vmx->__launched = vmx->loaded_vmcs->launched;
asm(
/* Store host registers */
@@ -6306,6 +6332,15 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
vmx->nested.current_vmptr = -1ull;
vmx->nested.current_vmcs12 = NULL;
+ vmx->perf_msrs_cnt = perf_guest_get_msrs_count();
+ if (vmx->perf_msrs_cnt> 0) {
+ vmx->perf_msrs = kmalloc(vmx->perf_msrs_cnt *
+ sizeof(struct perf_guest_switch_msr),
+ GFP_KERNEL);
+ if (!vmx->perf_msrs)
+ goto free_vmcs;
+ }
+
Do we really need a private buffer? Perhaps perf_guest_get_msrs() can
return a perf-internal buffer (but then, we will need to copy it for the
optimization above, but that's a separate issue).
--
error compiling committee.c: too many arguments to function
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