Commit bb44e0d1 authored by Jan Kiszka's avatar Jan Kiszka Committed by Marcelo Tosatti
Browse files

kvm: Improve reporting of fatal errors 



Report KVM_EXIT_UNKNOWN, KVM_EXIT_FAIL_ENTRY, and KVM_EXIT_EXCEPTION
with more details to stderr. The latter two are so far x86-only, so move
them into the arch-specific handler. Integrate the Intel real mode
warning on KVM_EXIT_FAIL_ENTRY that qemu-kvm carries, but actually
restrict it to Intel CPUs. Moreover, always dump the CPU state in case
we fail.

Signed-off-by: default avatarJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 73aaec4a

kvm-all.c

+8 −14
Original line number Diff line number Diff line
@@ -817,22 +817,22 @@ static int kvm_handle_io(uint16_t port, void *data, int direction, int size, 
#ifdef KVM_CAP_INTERNAL_ERROR_DATA

static int kvm_handle_internal_error(CPUState *env, struct kvm_run *run)

{



    fprintf(stderr, "KVM internal error.");

    if (kvm_check_extension(kvm_state, KVM_CAP_INTERNAL_ERROR_DATA)) {

        int i;



        fprintf(stderr, "KVM internal error. Suberror: %d\n",

                run->internal.suberror);



        fprintf(stderr, " Suberror: %d\n", run->internal.suberror);

        for (i = 0; i < run->internal.ndata; ++i) {

            fprintf(stderr, "extra data[%d]: %"PRIx64"\n",

                    i, (uint64_t)run->internal.data[i]);

        }

    } else {

        fprintf(stderr, "\n");

    }

    cpu_dump_state(env, stderr, fprintf, 0);

    if (run->internal.suberror == KVM_INTERNAL_ERROR_EMULATION) {

        fprintf(stderr, "emulation failure\n");

        if (!kvm_arch_stop_on_emulation_error(env)) {

            cpu_dump_state(env, stderr, fprintf, 0);

            return 0;

        }

    }
@@ -966,15 +966,8 @@ int kvm_cpu_exec(CPUState *env) 
            ret = 1;

            break;

        case KVM_EXIT_UNKNOWN:

            DPRINTF("kvm_exit_unknown\n");

            ret = -1;

            break;

        case KVM_EXIT_FAIL_ENTRY:

            DPRINTF("kvm_exit_fail_entry\n");

            ret = -1;

            break;

        case KVM_EXIT_EXCEPTION:

            DPRINTF("kvm_exit_exception\n");

            fprintf(stderr, "KVM: unknown exit, hardware reason %" PRIx64 "\n",

                    (uint64_t)run->hw.hardware_exit_reason);

            ret = -1;

            break;

#ifdef KVM_CAP_INTERNAL_ERROR_DATA
@@ -1001,6 +994,7 @@ int kvm_cpu_exec(CPUState *env) 
    } while (ret > 0);



    if (ret < 0) {

        cpu_dump_state(env, stderr, fprintf, 0);

        vm_stop(0);

        env->exit_request = 1;

    }

target-i386/cpu.h

+2 −0
Original line number Diff line number Diff line
@@ -874,6 +874,8 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, 
                   uint32_t *ecx, uint32_t *edx);

int cpu_x86_register (CPUX86State *env, const char *cpu_model);

void cpu_clear_apic_feature(CPUX86State *env);

void host_cpuid(uint32_t function, uint32_t count,

                uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx);



/* helper.c */

int cpu_x86_handle_mmu_fault(CPUX86State *env, target_ulong addr,

target-i386/cpuid.c

+2 −3
Original line number Diff line number Diff line
@@ -103,9 +103,8 @@ typedef struct model_features_t { 
int check_cpuid = 0;

int enforce_cpuid = 0;



static void host_cpuid(uint32_t function, uint32_t count,

                       uint32_t *eax, uint32_t *ebx,

                       uint32_t *ecx, uint32_t *edx)

void host_cpuid(uint32_t function, uint32_t count,

                uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx)

{

#if defined(CONFIG_KVM)

    uint32_t vec[4];

target-i386/kvm.c

+33 −0
Original line number Diff line number Diff line
@@ -1525,8 +1525,19 @@ static int kvm_handle_halt(CPUState *env) 
    return 1;

}



static bool host_supports_vmx(void)

{

    uint32_t ecx, unused;



    host_cpuid(1, 0, &unused, &unused, &ecx, &unused);

    return ecx & CPUID_EXT_VMX;

}



#define VMX_INVALID_GUEST_STATE 0x80000021



int kvm_arch_handle_exit(CPUState *env, struct kvm_run *run)

{

    uint64_t code;

    int ret = 0;



    switch (run->exit_reason) {
@@ -1537,6 +1548,28 @@ int kvm_arch_handle_exit(CPUState *env, struct kvm_run *run) 
    case KVM_EXIT_SET_TPR:

        ret = 1;

        break;

    case KVM_EXIT_FAIL_ENTRY:

        code = run->fail_entry.hardware_entry_failure_reason;

        fprintf(stderr, "KVM: entry failed, hardware error 0x%" PRIx64 "\n",

                code);

        if (host_supports_vmx() && code == VMX_INVALID_GUEST_STATE) {

            fprintf(stderr,

                    "\nIf you're runnning a guest on an Intel machine without "

                        "unrestricted mode\n"

                    "support, the failure can be most likely due to the guest "

                        "entering an invalid\n"

                    "state for Intel VT. For example, the guest maybe running "

                        "in big real mode\n"

                    "which is not supported on less recent Intel processors."

                        "\n\n");

        }

        ret = -1;

        break;

    case KVM_EXIT_EXCEPTION:

        fprintf(stderr, "KVM: exception %d exit (error code 0x%x)\n",

                run->ex.exception, run->ex.error_code);

        ret = -1;

        break;

    default:

        fprintf(stderr, "KVM: unknown exit reason %d\n", run->exit_reason);

        ret = -1;