KVM: Emulate hlt on real mode for Intel

This has two use cases: the bios can't boot from disk, and guest smp
bootstrap.

Signed-off-by: Avi Kivity <avi@qumranet.com>

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index ac358b8..d49b16c 100644 (file)
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -347,6 +347,7 @@ struct kvm_vcpu {
                        u32 ar;
                } tr, es, ds, fs, gs;
        } rmode;
+       int halt_request; /* real mode on Intel only */
 
        int cpuid_nent;
        struct kvm_cpuid_entry cpuid_entries[KVM_MAX_CPUID_ENTRIES];

diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 90abd3c..a1f51b9 100644 (file)
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -1608,8 +1608,13 @@ static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 
        if (vcpu->rmode.active &&
            handle_rmode_exception(vcpu, intr_info & INTR_INFO_VECTOR_MASK,
-                                                               error_code))
+                                                               error_code)) {
+               if (vcpu->halt_request) {
+                       vcpu->halt_request = 0;
+                       return kvm_emulate_halt(vcpu);
+               }
                return 1;
+       }
 
        if ((intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VECTOR_MASK)) == (INTR_TYPE_EXCEPTION | 1)) {
                kvm_run->exit_reason = KVM_EXIT_DEBUG;

diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index 6123c02..a4a8481 100644 (file)
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -143,7 +143,8 @@ static u8 opcode_table[256] = {
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        /* 0xF0 - 0xF7 */
        0, 0, 0, 0,
-       0, 0, ByteOp | DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM,
+       ImplicitOps, 0,
+       ByteOp | DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM,
        /* 0xF8 - 0xFF */
        0, 0, 0, 0,
        0, 0, ByteOp | DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM
@@ -1149,6 +1150,9 @@ special_insn:
        case 0xae ... 0xaf:     /* scas */
                DPRINTF("Urk! I don't handle SCAS.\n");
                goto cannot_emulate;
+       case 0xf4:              /* hlt */
+               ctxt->vcpu->halt_request = 1;
+               goto done;
        }
        goto writeback;