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
......@@ -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;
......
......@@ -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;
}
......
......@@ -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;
......
......@@ -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
......@@ -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;
......
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