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Commit b209749f authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: local APIC TPR access reporting facility 



Add a facility to report on accesses to the local apic tpr even if the
local apic is emulated in the kernel.  This is basically a hack that
allows userspace to patch Windows which tends to bang on the tpr a lot.

Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent 565f1fbd

arch/x86/kvm/lapic.c

+21 −0
Original line number Diff line number Diff line
@@ -551,6 +551,23 @@ static u32 apic_get_tmcct(struct kvm_lapic *apic) 
	return tmcct;

}



static void __report_tpr_access(struct kvm_lapic *apic, bool write)

{

	struct kvm_vcpu *vcpu = apic->vcpu;

	struct kvm_run *run = vcpu->run;



	set_bit(KVM_REQ_REPORT_TPR_ACCESS, &vcpu->requests);

	kvm_x86_ops->cache_regs(vcpu);

	run->tpr_access.rip = vcpu->arch.rip;

	run->tpr_access.is_write = write;

}



static inline void report_tpr_access(struct kvm_lapic *apic, bool write)

{

	if (apic->vcpu->arch.tpr_access_reporting)

		__report_tpr_access(apic, write);

}



static u32 __apic_read(struct kvm_lapic *apic, unsigned int offset)

{

	u32 val = 0;
@@ -568,6 +585,9 @@ static u32 __apic_read(struct kvm_lapic *apic, unsigned int offset) 
		val = apic_get_tmcct(apic);

		break;



	case APIC_TASKPRI:

		report_tpr_access(apic, false);

		/* fall thru */

	default:

		apic_update_ppr(apic);

		val = apic_get_reg(apic, offset);
@@ -677,6 +697,7 @@ static void apic_mmio_write(struct kvm_io_device *this, 
		break;



	case APIC_TASKPRI:

		report_tpr_access(apic, true);

		apic_set_tpr(apic, val & 0xff);

		break;

arch/x86/kvm/x86.c

+25 −0
Original line number Diff line number Diff line
@@ -684,6 +684,7 @@ int kvm_dev_ioctl_check_extension(long ext) 
	case KVM_CAP_USER_MEMORY:

	case KVM_CAP_SET_TSS_ADDR:

	case KVM_CAP_EXT_CPUID:

	case KVM_CAP_VAPIC:

		r = 1;

		break;

	default:
@@ -1055,6 +1056,15 @@ static int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, 
	return 0;

}



static int vcpu_ioctl_tpr_access_reporting(struct kvm_vcpu *vcpu,

					   struct kvm_tpr_access_ctl *tac)

{

	if (tac->flags)

		return -EINVAL;

	vcpu->arch.tpr_access_reporting = !!tac->enabled;

	return 0;

}



long kvm_arch_vcpu_ioctl(struct file *filp,

			 unsigned int ioctl, unsigned long arg)

{
@@ -1148,6 +1158,21 @@ long kvm_arch_vcpu_ioctl(struct file *filp, 
	case KVM_SET_MSRS:

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

		break;

	case KVM_TPR_ACCESS_REPORTING: {

		struct kvm_tpr_access_ctl tac;



		r = -EFAULT;

		if (copy_from_user(&tac, argp, sizeof tac))

			goto out;

		r = vcpu_ioctl_tpr_access_reporting(vcpu, &tac);

		if (r)

			goto out;

		r = -EFAULT;

		if (copy_to_user(argp, &tac, sizeof tac))

			goto out;

		r = 0;

		break;

	};

	default:

		r = -EINVAL;

	}

include/asm-x86/kvm_host.h

+1 −0
Original line number Diff line number Diff line
@@ -211,6 +211,7 @@ struct kvm_vcpu_arch { 
	int mp_state;

	int sipi_vector;

	u64 ia32_misc_enable_msr;

	bool tpr_access_reporting;



	struct kvm_mmu mmu;

include/linux/kvm.h

+17 −0
Original line number Diff line number Diff line
@@ -72,6 +72,7 @@ struct kvm_irqchip { 
#define KVM_EXIT_FAIL_ENTRY       9

#define KVM_EXIT_INTR             10

#define KVM_EXIT_SET_TPR          11

#define KVM_EXIT_TPR_ACCESS       12



/* for KVM_RUN, returned by mmap(vcpu_fd, offset=0) */

struct kvm_run {
@@ -130,6 +131,12 @@ struct kvm_run { 
			__u32 longmode;

			__u32 pad;

		} hypercall;

		/* KVM_EXIT_TPR_ACCESS */

		struct {

			__u64 rip;

			__u32 is_write;

			__u32 pad;

		} tpr_access;

		/* Fix the size of the union. */

		char padding[256];

	};
@@ -202,6 +209,13 @@ struct kvm_signal_mask { 
	__u8  sigset[0];

};



/* for KVM_TPR_ACCESS_REPORTING */

struct kvm_tpr_access_ctl {

	__u32 enabled;

	__u32 flags;

	__u32 reserved[8];

};



#define KVMIO 0xAE



/*
@@ -229,6 +243,7 @@ struct kvm_signal_mask { 
#define KVM_CAP_USER_MEMORY 3

#define KVM_CAP_SET_TSS_ADDR 4

#define KVM_CAP_EXT_CPUID 5

#define KVM_CAP_VAPIC 6



/*

 * ioctls for VM fds
@@ -274,5 +289,7 @@ struct kvm_signal_mask { 
#define KVM_SET_LAPIC             _IOW(KVMIO,  0x8f, struct kvm_lapic_state)

#define KVM_SET_CPUID2            _IOW(KVMIO,  0x90, struct kvm_cpuid2)

#define KVM_GET_CPUID2            _IOWR(KVMIO, 0x91, struct kvm_cpuid2)

/* Available with KVM_CAP_VAPIC */

#define KVM_TPR_ACCESS_REPORTING  _IOWR(KVMIO,  0x92, struct kvm_tpr_access_ctl)



#endif

include/linux/kvm_host.h

+1 −1
Original line number Diff line number Diff line
@@ -35,7 +35,7 @@ 
 * vcpu->requests bit members

 */

#define KVM_REQ_TLB_FLUSH          0



#define KVM_REQ_REPORT_TPR_ACCESS  2



struct kvm_vcpu;

extern struct kmem_cache *kvm_vcpu_cache;