[PATCH 52/58] KVM: Emulate hlt on real mode for Intel

Avi Kivity
2007-06-17T09:44:33Z

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

Signed-off-by: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
---
drivers/kvm/kvm.h | 1 +
drivers/kvm/vmx.c | 7 ++++++-
drivers/kvm/x86_emulate.c | 6 +++++-
3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index ac358b8..d49b16c 100644
--- 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
--- 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
--- 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;