Merge branch 'kvm-updates/2.6.35' of git://git.kernel.org/pub/scm/virt/kvm/kvm

[safe/jmp/linux-2.6] / arch / x86 / kvm / svm.c

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 96dc232..ce438e0 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -28,6 +28,7 @@
 #include <linux/ftrace_event.h>
 #include <linux/slab.h>
 
+#include <asm/tlbflush.h>
 #include <asm/desc.h>
 
 #include <asm/virtext.h>
@@ -56,6 +57,8 @@ MODULE_LICENSE("GPL");
 
 #define DEBUGCTL_RESERVED_BITS (~(0x3fULL))
 
+static bool erratum_383_found __read_mostly;
+
 static const u32 host_save_user_msrs[] = {
 #ifdef CONFIG_X86_64
        MSR_STAR, MSR_LSTAR, MSR_CSTAR, MSR_SYSCALL_MASK, MSR_KERNEL_GS_BASE,
@@ -374,6 +377,31 @@ static void svm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,
        svm->vmcb->control.event_inj_err = error_code;
 }
 
+static void svm_init_erratum_383(void)
+{
+       u32 low, high;
+       int err;
+       u64 val;
+
+       /* Only Fam10h is affected */
+       if (boot_cpu_data.x86 != 0x10)
+               return;
+
+       /* Use _safe variants to not break nested virtualization */
+       val = native_read_msr_safe(MSR_AMD64_DC_CFG, &err);
+       if (err)
+               return;
+
+       val |= (1ULL << 47);
+
+       low  = lower_32_bits(val);
+       high = upper_32_bits(val);
+
+       native_write_msr_safe(MSR_AMD64_DC_CFG, low, high);
+
+       erratum_383_found = true;
+}
+
 static int has_svm(void)
 {
        const char *msg;
@@ -429,6 +457,8 @@ static int svm_hardware_enable(void *garbage)
 
        wrmsrl(MSR_VM_HSAVE_PA, page_to_pfn(sd->save_area) << PAGE_SHIFT);
 
+       svm_init_erratum_383();
+
        return 0;
 }
 
@@ -1410,8 +1440,59 @@ static int nm_interception(struct vcpu_svm *svm)
        return 1;
 }
 
-static int mc_interception(struct vcpu_svm *svm)
+static bool is_erratum_383(void)
 {
+       int err, i;
+       u64 value;
+
+       if (!erratum_383_found)
+               return false;
+
+       value = native_read_msr_safe(MSR_IA32_MC0_STATUS, &err);
+       if (err)
+               return false;
+
+       /* Bit 62 may or may not be set for this mce */
+       value &= ~(1ULL << 62);
+
+       if (value != 0xb600000000010015ULL)
+               return false;
+
+       /* Clear MCi_STATUS registers */
+       for (i = 0; i < 6; ++i)
+               native_write_msr_safe(MSR_IA32_MCx_STATUS(i), 0, 0);
+
+       value = native_read_msr_safe(MSR_IA32_MCG_STATUS, &err);
+       if (!err) {
+               u32 low, high;
+
+               value &= ~(1ULL << 2);
+               low    = lower_32_bits(value);
+               high   = upper_32_bits(value);
+
+               native_write_msr_safe(MSR_IA32_MCG_STATUS, low, high);
+       }
+
+       /* Flush tlb to evict multi-match entries */
+       __flush_tlb_all();
+
+       return true;
+}
+
+static void svm_handle_mce(struct vcpu_svm *svm)
+{
+       if (is_erratum_383()) {
+               /*
+                * Erratum 383 triggered. Guest state is corrupt so kill the
+                * guest.
+                */
+               pr_err("KVM: Guest triggered AMD Erratum 383\n");
+
+               set_bit(KVM_REQ_TRIPLE_FAULT, &svm->vcpu.requests);
+
+               return;
+       }
+
        /*
         * On an #MC intercept the MCE handler is not called automatically in
         * the host. So do it by hand here.
@@ -1420,6 +1501,11 @@ static int mc_interception(struct vcpu_svm *svm)
                "int $0x12\n");
        /* not sure if we ever come back to this point */
 
+       return;
+}
+
+static int mc_interception(struct vcpu_svm *svm)
+{
        return 1;
 }
 
@@ -3088,6 +3174,14 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu)
                vcpu->arch.regs_avail &= ~(1 << VCPU_EXREG_PDPTR);
                vcpu->arch.regs_dirty &= ~(1 << VCPU_EXREG_PDPTR);
        }
+
+       /*
+        * We need to handle MC intercepts here before the vcpu has a chance to
+        * change the physical cpu
+        */
+       if (unlikely(svm->vmcb->control.exit_code ==
+                    SVM_EXIT_EXCP_BASE + MC_VECTOR))
+               svm_handle_mce(svm);
 }
 
 #undef R