diff options
author | Avi Kivity <avi@redhat.com> | 2010-04-28 16:40:38 +0300 |
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committer | Avi Kivity <avi@redhat.com> | 2010-05-19 11:36:31 +0300 |
commit | 61d2ef2ce3e0161bedf5d2867f546a8df77fa9bc (patch) | |
tree | d1e3423bac53d2222b4c607e15b29c6e7f9b546a /arch/x86 | |
parent | 5dfa3d170e17cbf9e4816a5ba2f5913c31c03e93 (diff) | |
download | op-kernel-dev-61d2ef2ce3e0161bedf5d2867f546a8df77fa9bc.zip op-kernel-dev-61d2ef2ce3e0161bedf5d2867f546a8df77fa9bc.tar.gz |
KVM: VMX: Add facility to atomically switch MSRs on guest entry/exit
Some guest msr values cannot be used on the host (for example. EFER.NX=0),
so we need to switch them atomically during guest entry or exit.
Add a facility to program the vmx msr autoload registers accordingly.
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/kvm/vmx.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 2e87296..ae22dcf 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -98,6 +98,8 @@ module_param(ple_gap, int, S_IRUGO); static int ple_window = KVM_VMX_DEFAULT_PLE_WINDOW; module_param(ple_window, int, S_IRUGO); +#define NR_AUTOLOAD_MSRS 1 + struct vmcs { u32 revision_id; u32 abort; @@ -125,6 +127,11 @@ struct vcpu_vmx { u64 msr_guest_kernel_gs_base; #endif struct vmcs *vmcs; + struct msr_autoload { + unsigned nr; + struct vmx_msr_entry guest[NR_AUTOLOAD_MSRS]; + struct vmx_msr_entry host[NR_AUTOLOAD_MSRS]; + } msr_autoload; struct { int loaded; u16 fs_sel, gs_sel, ldt_sel; @@ -595,6 +602,46 @@ static void update_exception_bitmap(struct kvm_vcpu *vcpu) vmcs_write32(EXCEPTION_BITMAP, eb); } +static void clear_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr) +{ + unsigned i; + struct msr_autoload *m = &vmx->msr_autoload; + + for (i = 0; i < m->nr; ++i) + if (m->guest[i].index == msr) + break; + + if (i == m->nr) + return; + --m->nr; + m->guest[i] = m->guest[m->nr]; + m->host[i] = m->host[m->nr]; + vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->nr); + vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, m->nr); +} + +static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr, + u64 guest_val, u64 host_val) +{ + unsigned i; + struct msr_autoload *m = &vmx->msr_autoload; + + for (i = 0; i < m->nr; ++i) + if (m->guest[i].index == msr) + break; + + if (i == m->nr) { + ++m->nr; + vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->nr); + vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, m->nr); + } + + m->guest[i].index = msr; + m->guest[i].value = guest_val; + m->host[i].index = msr; + m->host[i].value = host_val; +} + static void reload_tss(void) { /* @@ -2470,7 +2517,9 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx) vmcs_writel(HOST_RIP, kvm_vmx_return); /* 22.2.5 */ vmcs_write32(VM_EXIT_MSR_STORE_COUNT, 0); vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, 0); + vmcs_write64(VM_EXIT_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.host)); vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, 0); + vmcs_write64(VM_ENTRY_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.guest)); rdmsr(MSR_IA32_SYSENTER_CS, host_sysenter_cs, junk); vmcs_write32(HOST_IA32_SYSENTER_CS, host_sysenter_cs); |