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Commit 35f3f286 authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: x86 emulator: implement rdmsr and wrmsr 



Allow real-mode emulation of rdmsr and wrmsr.  This allows smp Windows to
boot, presumably for its sipi trampoline.

Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent 90cb0529

drivers/kvm/kvm.h

+2 −0
Original line number Diff line number Diff line
@@ -569,6 +569,8 @@ void realmode_lmsw(struct kvm_vcpu *vcpu, unsigned long msw, 
unsigned long realmode_get_cr(struct kvm_vcpu *vcpu, int cr);

void realmode_set_cr(struct kvm_vcpu *vcpu, int cr, unsigned long value,

		     unsigned long *rflags);

int kvm_get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *data);

int kvm_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data);



struct x86_emulate_ctxt;

drivers/kvm/kvm_main.c

+4 −4
Original line number Diff line number Diff line
@@ -1517,7 +1517,7 @@ EXPORT_SYMBOL_GPL(kvm_get_msr_common); 
 * Returns 0 on success, non-0 otherwise.

 * Assumes vcpu_load() was already called.

 */

static int get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)

int kvm_get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)

{

	return kvm_arch_ops->get_msr(vcpu, msr_index, pdata);

}
@@ -1595,7 +1595,7 @@ EXPORT_SYMBOL_GPL(kvm_set_msr_common); 
 * Returns 0 on success, non-0 otherwise.

 * Assumes vcpu_load() was already called.

 */

static int set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)

int kvm_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)

{

	return kvm_arch_ops->set_msr(vcpu, msr_index, data);

}
@@ -2133,7 +2133,7 @@ static __init void kvm_init_msr_list(void) 
 */

static int do_set_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data)

{

	return set_msr(vcpu, index, *data);

	return kvm_set_msr(vcpu, index, *data);

}



/*
@@ -2617,7 +2617,7 @@ static long kvm_vcpu_ioctl(struct file *filp, 
		break;

	}

	case KVM_GET_MSRS:

		r = msr_io(vcpu, argp, get_msr, 1);

		r = msr_io(vcpu, argp, kvm_get_msr, 1);

		break;

	case KVM_SET_MSRS:

		r = msr_io(vcpu, argp, do_set_msr, 0);

drivers/kvm/x86_emulate.c

+25 −1
Original line number Diff line number Diff line
@@ -163,7 +163,7 @@ static u16 twobyte_table[256] = { 
	ModRM | ImplicitOps, ModRM, ModRM | ImplicitOps, ModRM, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	/* 0x30 - 0x3F */

	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

	ImplicitOps, 0, ImplicitOps, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

	/* 0x40 - 0x47 */

	DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,

	DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
@@ -486,6 +486,7 @@ x86_emulate_memop(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
	unsigned long modrm_ea;

	int use_modrm_ea, index_reg = 0, base_reg = 0, scale, rip_relative = 0;

	int no_wb = 0;

	u64 msr_data;



	/* Shadow copy of register state. Committed on successful emulation. */

	unsigned long _regs[NR_VCPU_REGS];
@@ -1344,6 +1345,29 @@ x86_emulate_memop(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
			goto cannot_emulate;

		realmode_set_cr(ctxt->vcpu, modrm_reg, modrm_val, &_eflags);

		break;

	case 0x30:

		/* wrmsr */

		msr_data = (u32)_regs[VCPU_REGS_RAX]

			| ((u64)_regs[VCPU_REGS_RDX] << 32);

		rc = kvm_set_msr(ctxt->vcpu, _regs[VCPU_REGS_RCX], msr_data);

		if (rc) {

			kvm_arch_ops->inject_gp(ctxt->vcpu, 0);

			_eip = ctxt->vcpu->rip;

		}

		rc = X86EMUL_CONTINUE;

		break;

	case 0x32:

		/* rdmsr */

		rc = kvm_get_msr(ctxt->vcpu, _regs[VCPU_REGS_RCX], &msr_data);

		if (rc) {

			kvm_arch_ops->inject_gp(ctxt->vcpu, 0);

			_eip = ctxt->vcpu->rip;

		} else {

			_regs[VCPU_REGS_RAX] = (u32)msr_data;

			_regs[VCPU_REGS_RDX] = msr_data >> 32;

		}

		rc = X86EMUL_CONTINUE;

		break;

	case 0xc7:		/* Grp9 (cmpxchg8b) */

		{

			u64 old, new;