| Message ID | 1343991434-8241-1-git-send-email-stefan.bader@canonical.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 08/03/2012 01:57 PM, Stefan Bader wrote: >> No, you're backporting the entire feature. All we need is to expose >> RDPMC intercept to the guest. > > Oh well, I thought that was the thing you asked for... Sorry for being unclear. > >> It should be sufficient to backport the bits in >> nested_vmx_setup_ctls_msrs() and nested_vmx_exit_handled(). > > Ok, how about that? It is probably wrong again, but at least it > allows to load the kvm-intel module from within a nested guest > and not having the feature pretend to fail seems the closest > thing to do... > > --- > > From 0aeb99348363b7aeb2b0bd92428cb212159fa468 Mon Sep 17 00:00:00 2001 > From: Stefan Bader <stefan.bader@canonical.com> > Date: Thu, 10 Nov 2011 14:57:25 +0200 > Subject: [PATCH] KVM: VMX: Fake intercept RDPMC > > Based on commit fee84b079d5ddee2247b5c1f53162c330c622902 upstream. > > Intercept RDPMC and forward it to the PMU emulation code. > > But drop the requirement for the feature being present and instead > of forwarding, cause a GP as if the call had failed. > > BugLink: http://bugs.launchpad.net/bugs/1031090 > Signed-off-by: Stefan Bader <stefan.bader@canonical.com> > --- > arch/x86/kvm/vmx.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 7315488..fc937f2 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -1956,6 +1956,7 @@ static __init void nested_vmx_setup_ctls_msrs(void) > #endif > CPU_BASED_MOV_DR_EXITING | CPU_BASED_UNCOND_IO_EXITING | > CPU_BASED_USE_IO_BITMAPS | CPU_BASED_MONITOR_EXITING | > + CPU_BASED_RDPMC_EXITING | > CPU_BASED_ACTIVATE_SECONDARY_CONTROLS; > /* > * We can allow some features even when not supported by the > @@ -4613,6 +4614,14 @@ static int handle_invlpg(struct kvm_vcpu *vcpu) > return 1; > } > > +static int handle_rdpmc(struct kvm_vcpu *vcpu) > +{ > + /* Instead of implementing the feature, cause a GP */ > + kvm_complete_insn_gp(vcpu, 1); > + > + return 1; > +} In fact this should never be called, since we never request RDPMC exiting for L1. > + > static int handle_wbinvd(struct kvm_vcpu *vcpu) > { > skip_emulated_instruction(vcpu); > @@ -5563,6 +5572,7 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = { > [EXIT_REASON_HLT] = handle_halt, > [EXIT_REASON_INVD] = handle_invd, > [EXIT_REASON_INVLPG] = handle_invlpg, > + [EXIT_REASON_RDPMC] = handle_rdpmc, > [EXIT_REASON_VMCALL] = handle_vmcall, > [EXIT_REASON_VMCLEAR] = handle_vmclear, > [EXIT_REASON_VMLAUNCH] = handle_vmlaunch, > Provided you backport the bit in nested_vmx_exit_handled(). That takes the L2->L1 RDPMC exit and forwards it to L1.
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 7315488..fc937f2 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1956,6 +1956,7 @@ static __init void nested_vmx_setup_ctls_msrs(void) #endif CPU_BASED_MOV_DR_EXITING | CPU_BASED_UNCOND_IO_EXITING | CPU_BASED_USE_IO_BITMAPS | CPU_BASED_MONITOR_EXITING | + CPU_BASED_RDPMC_EXITING | CPU_BASED_ACTIVATE_SECONDARY_CONTROLS; /* * We can allow some features even when not supported by the @@ -4613,6 +4614,14 @@ static int handle_invlpg(struct kvm_vcpu *vcpu) return 1; } +static int handle_rdpmc(struct kvm_vcpu *vcpu) +{ + /* Instead of implementing the feature, cause a GP */ + kvm_complete_insn_gp(vcpu, 1); + + return 1; +} + static int handle_wbinvd(struct kvm_vcpu *vcpu) { skip_emulated_instruction(vcpu); @@ -5563,6 +5572,7 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = { [EXIT_REASON_HLT] = handle_halt, [EXIT_REASON_INVD] = handle_invd, [EXIT_REASON_INVLPG] = handle_invlpg, + [EXIT_REASON_RDPMC] = handle_rdpmc, [EXIT_REASON_VMCALL] = handle_vmcall, [EXIT_REASON_VMCLEAR] = handle_vmclear, [EXIT_REASON_VMLAUNCH] = handle_vmlaunch,