Commit 10388a07 authored by Gleb Natapov's avatar Gleb Natapov Committed by Marcelo Tosatti
Browse files

KVM: Add HYPER-V apic access MSRs 



Implement HYPER-V apic MSRs. Spec defines three MSRs that speed-up
access to EOI/TPR/ICR apic registers for PV guests.

Signed-off-by: default avatarGleb Natapov <gleb@redhat.com>
Signed-off-by: default avatarVadim Rozenfeld <vrozenfe@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 55cd8e5a

arch/x86/include/asm/kvm_host.h

+2 −0
Original line number Diff line number Diff line
@@ -363,6 +363,8 @@ struct kvm_vcpu_arch { 
	/* used for guest single stepping over the given code position */

	u16 singlestep_cs;

	unsigned long singlestep_rip;

	/* fields used by HYPER-V emulation */

	u64 hv_vapic;

};



struct kvm_mem_alias {

arch/x86/kvm/lapic.c

+31 −0
Original line number Diff line number Diff line
@@ -1246,3 +1246,34 @@ int kvm_x2apic_msr_read(struct kvm_vcpu *vcpu, u32 msr, u64 *data) 


	return 0;

}



int kvm_hv_vapic_msr_write(struct kvm_vcpu *vcpu, u32 reg, u64 data)

{

	struct kvm_lapic *apic = vcpu->arch.apic;



	if (!irqchip_in_kernel(vcpu->kvm))

		return 1;



	/* if this is ICR write vector before command */

	if (reg == APIC_ICR)

		apic_reg_write(apic, APIC_ICR2, (u32)(data >> 32));

	return apic_reg_write(apic, reg, (u32)data);

}



int kvm_hv_vapic_msr_read(struct kvm_vcpu *vcpu, u32 reg, u64 *data)

{

	struct kvm_lapic *apic = vcpu->arch.apic;

	u32 low, high = 0;



	if (!irqchip_in_kernel(vcpu->kvm))

		return 1;



	if (apic_reg_read(apic, reg, 4, &low))

		return 1;

	if (reg == APIC_ICR)

		apic_reg_read(apic, APIC_ICR2, 4, &high);



	*data = (((u64)high) << 32) | low;



	return 0;

}

arch/x86/kvm/lapic.h

+8 −0
Original line number Diff line number Diff line
@@ -48,4 +48,12 @@ void kvm_lapic_sync_to_vapic(struct kvm_vcpu *vcpu); 


int kvm_x2apic_msr_write(struct kvm_vcpu *vcpu, u32 msr, u64 data);

int kvm_x2apic_msr_read(struct kvm_vcpu *vcpu, u32 msr, u64 *data);



int kvm_hv_vapic_msr_write(struct kvm_vcpu *vcpu, u32 msr, u64 data);

int kvm_hv_vapic_msr_read(struct kvm_vcpu *vcpu, u32 msr, u64 *data);



static inline bool kvm_hv_vapic_assist_page_enabled(struct kvm_vcpu *vcpu)

{

	return vcpu->arch.hv_vapic & HV_X64_MSR_APIC_ASSIST_PAGE_ENABLE;

}

#endif

arch/x86/kvm/x86.c

+38 −4
Original line number Diff line number Diff line
@@ -622,10 +622,11 @@ static inline u32 bit(int bitno) 
 * kvm-specific. Those are put in the beginning of the list.

 */



#define KVM_SAVE_MSRS_BEGIN	4

#define KVM_SAVE_MSRS_BEGIN	5

static u32 msrs_to_save[] = {

	MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK,

	HV_X64_MSR_GUEST_OS_ID, HV_X64_MSR_HYPERCALL,

	HV_X64_MSR_APIC_ASSIST_PAGE,

	MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,

	MSR_K6_STAR,

#ifdef CONFIG_X86_64
@@ -1067,12 +1068,38 @@ static int set_msr_hyperv_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data) 


static int set_msr_hyperv(struct kvm_vcpu *vcpu, u32 msr, u64 data)

{

	pr_unimpl(vcpu, "HYPER-V unimplemented wrmsr: 0x%x data 0x%llx\n",

		  msr, data);

	switch (msr) {

	case HV_X64_MSR_APIC_ASSIST_PAGE: {

		unsigned long addr;



		if (!(data & HV_X64_MSR_APIC_ASSIST_PAGE_ENABLE)) {

			vcpu->arch.hv_vapic = data;

			break;

		}

		addr = gfn_to_hva(vcpu->kvm, data >>

				  HV_X64_MSR_APIC_ASSIST_PAGE_ADDRESS_SHIFT);

		if (kvm_is_error_hva(addr))

			return 1;

		if (clear_user((void __user *)addr, PAGE_SIZE))

			return 1;

		vcpu->arch.hv_vapic = data;

		break;

	}

	case HV_X64_MSR_EOI:

		return kvm_hv_vapic_msr_write(vcpu, APIC_EOI, data);

	case HV_X64_MSR_ICR:

		return kvm_hv_vapic_msr_write(vcpu, APIC_ICR, data);

	case HV_X64_MSR_TPR:

		return kvm_hv_vapic_msr_write(vcpu, APIC_TASKPRI, data);

	default:

		pr_unimpl(vcpu, "HYPER-V unimplemented wrmsr: 0x%x "

			  "data 0x%llx\n", msr, data);

		return 1;

	}



	return 0;

}



int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)

{

	switch (msr) {
@@ -1330,6 +1357,12 @@ static int get_msr_hyperv(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) 
				data = r;

		break;

	}

	case HV_X64_MSR_EOI:

		return kvm_hv_vapic_msr_read(vcpu, APIC_EOI, pdata);

	case HV_X64_MSR_ICR:

		return kvm_hv_vapic_msr_read(vcpu, APIC_ICR, pdata);

	case HV_X64_MSR_TPR:

		return kvm_hv_vapic_msr_read(vcpu, APIC_TASKPRI, pdata);

	default:

		pr_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);

		return 1;
@@ -1530,6 +1563,7 @@ int kvm_dev_ioctl_check_extension(long ext) 
	case KVM_CAP_ADJUST_CLOCK:

	case KVM_CAP_VCPU_EVENTS:

	case KVM_CAP_HYPERV:

	case KVM_CAP_HYPERV_VAPIC:

		r = 1;

		break;

	case KVM_CAP_COALESCED_MMIO:

include/linux/kvm.h

+1 −0
Original line number Diff line number Diff line
@@ -498,6 +498,7 @@ struct kvm_ioeventfd { 
#define KVM_CAP_S390_PSW 42

#define KVM_CAP_PPC_SEGSTATE 43

#define KVM_CAP_HYPERV 44

#define KVM_CAP_HYPERV_VAPIC 45



#ifdef KVM_CAP_IRQ_ROUTING

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