MCE: Relay UCR MCE to guest

Port qemu-kvm's

commit 4b62fff1101a7ad77553147717a8bd3bf79df7ef
Author: Huang Ying <ying.huang@intel.com>
Date:   Mon Sep 21 10:43:25 2009 +0800

    MCE: Relay UCR MCE to guest

    UCR (uncorrected recovery) MCE is supported in recent Intel CPUs,
    where some hardware error such as some memory error can be reported
    without PCC (processor context corrupted). To recover from such MCE,
    the corresponding memory will be unmapped, and all processes accessing
    the memory will be killed via SIGBUS.

    For KVM, if QEMU/KVM is killed, all guest processes will be killed
    too. So we relay SIGBUS from host OS to guest system via a UCR MCE
    injection. Then guest OS can isolate corresponding memory and kill
    necessary guest processes only. SIGBUS sent to main thread (not VCPU
    threads) will be broadcast to all VCPU threads as UCR MCE.

aliguori: fix build

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

4 files changed, 197 insertions, 6 deletions

diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index 77eeab185e..85ed30f7d3 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -250,16 +250,32 @@
 #define PG_ERROR_RSVD_MASK 0x08
 #define PG_ERROR_I_D_MASK  0x10
 
-#define MCG_CTL_P	(1UL<<8)   /* MCG_CAP register available */
+#define MCG_CTL_P	(1ULL<<8)   /* MCG_CAP register available */
+#define MCG_SER_P	(1ULL<<24) /* MCA recovery/new status bits */
 
-#define MCE_CAP_DEF	MCG_CTL_P
+#define MCE_CAP_DEF	(MCG_CTL_P|MCG_SER_P)
 #define MCE_BANKS_DEF	10
 
+#define MCG_STATUS_RIPV	(1ULL<<0)   /* restart ip valid */
+#define MCG_STATUS_EIPV	(1ULL<<1)   /* ip points to correct instruction */
 #define MCG_STATUS_MCIP	(1ULL<<2)   /* machine check in progress */
 
 #define MCI_STATUS_VAL	(1ULL<<63)  /* valid error */
 #define MCI_STATUS_OVER	(1ULL<<62)  /* previous errors lost */
 #define MCI_STATUS_UC	(1ULL<<61)  /* uncorrected error */
+#define MCI_STATUS_EN	(1ULL<<60)  /* error enabled */
+#define MCI_STATUS_MISCV (1ULL<<59) /* misc error reg. valid */
+#define MCI_STATUS_ADDRV (1ULL<<58) /* addr reg. valid */
+#define MCI_STATUS_PCC	(1ULL<<57)  /* processor context corrupt */
+#define MCI_STATUS_S	(1ULL<<56)  /* Signaled machine check */
+#define MCI_STATUS_AR	(1ULL<<55)  /* Action required */
+
+/* MISC register defines */
+#define MCM_ADDR_SEGOFF	0	/* segment offset */
+#define MCM_ADDR_LINEAR	1	/* linear address */
+#define MCM_ADDR_PHYS	2	/* physical address */
+#define MCM_ADDR_MEM	3	/* memory address */
+#define MCM_ADDR_GENERIC 7	/* generic */
 
 #define MSR_IA32_TSC                    0x10
 #define MSR_IA32_APICBASE               0x1b
diff --git a/target-i386/helper.c b/target-i386/helper.c
index 4b430dd374..4fff4a871f 100644
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -1032,7 +1032,7 @@ void cpu_inject_x86_mce(CPUState *cenv, int bank, uint64_t status,
         return;
 
     if (kvm_enabled()) {
-        kvm_inject_x86_mce(cenv, bank, status, mcg_status, addr, misc);
+        kvm_inject_x86_mce(cenv, bank, status, mcg_status, addr, misc, 0);
         return;
     }
 
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 343fb022c8..0161f6d2fb 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -46,6 +46,13 @@
 #define MSR_KVM_WALL_CLOCK  0x11
 #define MSR_KVM_SYSTEM_TIME 0x12
 
+#ifndef BUS_MCEERR_AR
+#define BUS_MCEERR_AR 4
+#endif
+#ifndef BUS_MCEERR_AO
+#define BUS_MCEERR_AO 5
+#endif
+
 #ifdef KVM_CAP_EXT_CPUID
 
 static struct kvm_cpuid2 *try_get_cpuid(KVMState *s, int max)
@@ -192,10 +199,39 @@ static int kvm_set_mce(CPUState *env, struct kvm_x86_mce *m)
     return kvm_vcpu_ioctl(env, KVM_X86_SET_MCE, m);
 }
 
+static int kvm_get_msr(CPUState *env, struct kvm_msr_entry *msrs, int n)
+{
+    struct kvm_msrs *kmsrs = qemu_malloc(sizeof *kmsrs + n * sizeof *msrs);
+    int r;
+
+    kmsrs->nmsrs = n;
+    memcpy(kmsrs->entries, msrs, n * sizeof *msrs);
+    r = kvm_vcpu_ioctl(env, KVM_GET_MSRS, kmsrs);
+    memcpy(msrs, kmsrs->entries, n * sizeof *msrs);
+    free(kmsrs);
+    return r;
+}
+
+/* FIXME: kill this and kvm_get_msr, use env->mcg_status instead */
+static int kvm_mce_in_exception(CPUState *env)
+{
+    struct kvm_msr_entry msr_mcg_status = {
+        .index = MSR_MCG_STATUS,
+    };
+    int r;
+
+    r = kvm_get_msr(env, &msr_mcg_status, 1);
+    if (r == -1 || r == 0) {
+        return -1;
+    }
+    return !!(msr_mcg_status.data & MCG_STATUS_MCIP);
+}
+
 struct kvm_x86_mce_data
 {
     CPUState *env;
     struct kvm_x86_mce *mce;
+    int abort_on_error;
 };
 
 static void kvm_do_inject_x86_mce(void *_data)
@@ -203,14 +239,26 @@ static void kvm_do_inject_x86_mce(void *_data)
     struct kvm_x86_mce_data *data = _data;
     int r;
 
+    /* If there is an MCE excpetion being processed, ignore this SRAO MCE */
+    r = kvm_mce_in_exception(data->env);
+    if (r == -1)
+        fprintf(stderr, "Failed to get MCE status\n");
+    else if (r && !(data->mce->status & MCI_STATUS_AR))
+        return;
+
     r = kvm_set_mce(data->env, data->mce);
-    if (r < 0)
+    if (r < 0) {
         perror("kvm_set_mce FAILED");
+        if (data->abort_on_error) {
+            abort();
+        }
+    }
 }
 #endif
 
 void kvm_inject_x86_mce(CPUState *cenv, int bank, uint64_t status,
-                        uint64_t mcg_status, uint64_t addr, uint64_t misc)
+                        uint64_t mcg_status, uint64_t addr, uint64_t misc,
+                        int abort_on_error)
 {
 #ifdef KVM_CAP_MCE
     struct kvm_x86_mce mce = {
@@ -225,7 +273,15 @@ void kvm_inject_x86_mce(CPUState *cenv, int bank, uint64_t status,
             .mce = &mce,
     };
 
+    if (!cenv->mcg_cap) {
+        fprintf(stderr, "MCE support is not enabled!\n");
+        return;
+    }
+
     run_on_cpu(cenv, kvm_do_inject_x86_mce, &data);
+#else
+    if (abort_on_error)
+        abort();
 #endif
 }
 
@@ -1528,3 +1584,121 @@ bool kvm_arch_stop_on_emulation_error(CPUState *env)
               ((env->segs[R_CS].selector  & 3) != 3);
 }
 
+static void hardware_memory_error(void)
+{
+    fprintf(stderr, "Hardware memory error!\n");
+    exit(1);
+}
+
+int kvm_on_sigbus_vcpu(CPUState *env, int code, void *addr)
+{
+#if defined(KVM_CAP_MCE)
+    struct kvm_x86_mce mce = {
+            .bank = 9,
+    };
+    void *vaddr;
+    ram_addr_t ram_addr;
+    target_phys_addr_t paddr;
+    int r;
+
+    if ((env->mcg_cap & MCG_SER_P) && addr
+        && (code == BUS_MCEERR_AR
+            || code == BUS_MCEERR_AO)) {
+        if (code == BUS_MCEERR_AR) {
+            /* Fake an Intel architectural Data Load SRAR UCR */
+            mce.status = MCI_STATUS_VAL | MCI_STATUS_UC | MCI_STATUS_EN
+                | MCI_STATUS_MISCV | MCI_STATUS_ADDRV | MCI_STATUS_S
+                | MCI_STATUS_AR | 0x134;
+            mce.misc = (MCM_ADDR_PHYS << 6) | 0xc;
+            mce.mcg_status = MCG_STATUS_MCIP | MCG_STATUS_EIPV;
+        } else {
+            /*
+             * If there is an MCE excpetion being processed, ignore
+             * this SRAO MCE
+             */
+            r = kvm_mce_in_exception(env);
+            if (r == -1) {
+                fprintf(stderr, "Failed to get MCE status\n");
+            } else if (r) {
+                return 0;
+            }
+            /* Fake an Intel architectural Memory scrubbing UCR */
+            mce.status = MCI_STATUS_VAL | MCI_STATUS_UC | MCI_STATUS_EN
+                | MCI_STATUS_MISCV | MCI_STATUS_ADDRV | MCI_STATUS_S
+                | 0xc0;
+            mce.misc = (MCM_ADDR_PHYS << 6) | 0xc;
+            mce.mcg_status = MCG_STATUS_MCIP | MCG_STATUS_RIPV;
+        }
+        vaddr = (void *)addr;
+        if (qemu_ram_addr_from_host(vaddr, &ram_addr) ||
+            !kvm_physical_memory_addr_from_ram(env->kvm_state, ram_addr, &paddr)) {
+            fprintf(stderr, "Hardware memory error for memory used by "
+                    "QEMU itself instead of guest system!\n");
+            /* Hope we are lucky for AO MCE */
+            if (code == BUS_MCEERR_AO) {
+                return 0;
+            } else {
+                hardware_memory_error();
+            }
+        }
+        mce.addr = paddr;
+        r = kvm_set_mce(env, &mce);
+        if (r < 0) {
+            fprintf(stderr, "kvm_set_mce: %s\n", strerror(errno));
+            abort();
+        }
+    } else
+#endif
+    {
+        if (code == BUS_MCEERR_AO) {
+            return 0;
+        } else if (code == BUS_MCEERR_AR) {
+            hardware_memory_error();
+        } else {
+            return 1;
+        }
+    }
+    return 0;
+}
+
+int kvm_on_sigbus(int code, void *addr)
+{
+#if defined(KVM_CAP_MCE)
+    if ((first_cpu->mcg_cap & MCG_SER_P) && addr && code == BUS_MCEERR_AO) {
+        uint64_t status;
+        void *vaddr;
+        ram_addr_t ram_addr;
+        target_phys_addr_t paddr;
+        CPUState *cenv;
+
+        /* Hope we are lucky for AO MCE */
+        vaddr = addr;
+        if (qemu_ram_addr_from_host(vaddr, &ram_addr) ||
+            !kvm_physical_memory_addr_from_ram(first_cpu->kvm_state, ram_addr, &paddr)) {
+            fprintf(stderr, "Hardware memory error for memory used by "
+                    "QEMU itself instead of guest system!: %p\n", addr);
+            return 0;
+        }
+        status = MCI_STATUS_VAL | MCI_STATUS_UC | MCI_STATUS_EN
+            | MCI_STATUS_MISCV | MCI_STATUS_ADDRV | MCI_STATUS_S
+            | 0xc0;
+        kvm_inject_x86_mce(first_cpu, 9, status,
+                           MCG_STATUS_MCIP | MCG_STATUS_RIPV, paddr,
+                           (MCM_ADDR_PHYS << 6) | 0xc, 1);
+        for (cenv = first_cpu->next_cpu; cenv != NULL; cenv = cenv->next_cpu) {
+            kvm_inject_x86_mce(cenv, 1, MCI_STATUS_VAL | MCI_STATUS_UC,
+                               MCG_STATUS_MCIP | MCG_STATUS_RIPV, 0, 0, 1);
+        }
+    } else
+#endif
+    {
+        if (code == BUS_MCEERR_AO) {
+            return 0;
+        } else if (code == BUS_MCEERR_AR) {
+            hardware_memory_error();
+        } else {
+            return 1;
+        }
+    }
+    return 0;
+}
diff --git a/target-i386/kvm_x86.h b/target-i386/kvm_x86.h
index c1ebd24fcf..04932cf4c8 100644
--- a/target-i386/kvm_x86.h
+++ b/target-i386/kvm_x86.h
@@ -16,6 +16,7 @@
 #define __KVM_X86_H__
 
 void kvm_inject_x86_mce(CPUState *cenv, int bank, uint64_t status,
-                        uint64_t mcg_status, uint64_t addr, uint64_t misc);
+                        uint64_t mcg_status, uint64_t addr, uint64_t misc,
+                        int abort_on_error);
 
 #endif