svm: Manage vcpu load/unload when enable AVIC

When a vcpu is loaded/unloaded to a physical core, we need to update
host physical APIC ID information in the Physical APIC-ID table
accordingly.

Also, when vCPU is blocking/un-blocking (due to halt instruction),
we need to make sure that the is-running bit in set accordingly in the
physical APIC-ID table.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
[Return void from new functions, add WARN_ON when they returned negative
 errno; split load and put into separate function as they have almost
 nothing in common. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Suravee Suthikulpanit 2016-05-04 14:09:52 -05:00 committed by Paolo Bonzini
parent 3bbf3565f4
commit 8221c13700

View File

@ -35,6 +35,7 @@
#include <linux/trace_events.h>
#include <linux/slab.h>
#include <asm/apic.h>
#include <asm/perf_event.h>
#include <asm/tlbflush.h>
#include <asm/desc.h>
@ -183,6 +184,7 @@ struct vcpu_svm {
u32 ldr_reg;
struct page *avic_backing_page;
u64 *avic_physical_id_cache;
bool avic_is_running;
};
#define AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK (0xFF)
@ -1316,6 +1318,72 @@ static int avic_vm_init(struct kvm *kvm)
return err;
}
/**
* This function is called during VCPU halt/unhalt.
*/
static void avic_set_running(struct kvm_vcpu *vcpu, bool is_run)
{
u64 entry;
int h_physical_id = __default_cpu_present_to_apicid(vcpu->cpu);
struct vcpu_svm *svm = to_svm(vcpu);
if (!kvm_vcpu_apicv_active(vcpu))
return;
svm->avic_is_running = is_run;
/* ID = 0xff (broadcast), ID > 0xff (reserved) */
if (WARN_ON(h_physical_id >= AVIC_MAX_PHYSICAL_ID_COUNT))
return;
entry = READ_ONCE(*(svm->avic_physical_id_cache));
WARN_ON(is_run == !!(entry & AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK));
entry &= ~AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK;
if (is_run)
entry |= AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK;
WRITE_ONCE(*(svm->avic_physical_id_cache), entry);
}
static void avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
u64 entry;
/* ID = 0xff (broadcast), ID > 0xff (reserved) */
int h_physical_id = __default_cpu_present_to_apicid(cpu);
struct vcpu_svm *svm = to_svm(vcpu);
if (!kvm_vcpu_apicv_active(vcpu))
return;
if (WARN_ON(h_physical_id >= AVIC_MAX_PHYSICAL_ID_COUNT))
return;
entry = READ_ONCE(*(svm->avic_physical_id_cache));
WARN_ON(entry & AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK);
entry &= ~AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK;
entry |= (h_physical_id & AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK);
entry &= ~AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK;
if (svm->avic_is_running)
entry |= AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK;
WRITE_ONCE(*(svm->avic_physical_id_cache), entry);
}
static void avic_vcpu_put(struct kvm_vcpu *vcpu)
{
u64 entry;
struct vcpu_svm *svm = to_svm(vcpu);
if (!kvm_vcpu_apicv_active(vcpu))
return;
entry = READ_ONCE(*(svm->avic_physical_id_cache));
entry &= ~AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK;
WRITE_ONCE(*(svm->avic_physical_id_cache), entry);
}
static void svm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
{
struct vcpu_svm *svm = to_svm(vcpu);
@ -1379,6 +1447,11 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id)
goto free_page4;
}
/* We initialize this flag to true to make sure that the is_running
* bit would be set the first time the vcpu is loaded.
*/
svm->avic_is_running = true;
svm->nested.hsave = page_address(hsave_page);
svm->msrpm = page_address(msrpm_pages);
@ -1455,6 +1528,8 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
/* This assumes that the kernel never uses MSR_TSC_AUX */
if (static_cpu_has(X86_FEATURE_RDTSCP))
wrmsrl(MSR_TSC_AUX, svm->tsc_aux);
avic_vcpu_load(vcpu, cpu);
}
static void svm_vcpu_put(struct kvm_vcpu *vcpu)
@ -1462,6 +1537,8 @@ static void svm_vcpu_put(struct kvm_vcpu *vcpu)
struct vcpu_svm *svm = to_svm(vcpu);
int i;
avic_vcpu_put(vcpu);
++vcpu->stat.host_state_reload;
kvm_load_ldt(svm->host.ldt);
#ifdef CONFIG_X86_64
@ -1477,6 +1554,16 @@ static void svm_vcpu_put(struct kvm_vcpu *vcpu)
wrmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);
}
static void svm_vcpu_blocking(struct kvm_vcpu *vcpu)
{
avic_set_running(vcpu, false);
}
static void svm_vcpu_unblocking(struct kvm_vcpu *vcpu)
{
avic_set_running(vcpu, true);
}
static unsigned long svm_get_rflags(struct kvm_vcpu *vcpu)
{
return to_svm(vcpu)->vmcb->save.rflags;
@ -4884,6 +4971,8 @@ static struct kvm_x86_ops svm_x86_ops = {
.prepare_guest_switch = svm_prepare_guest_switch,
.vcpu_load = svm_vcpu_load,
.vcpu_put = svm_vcpu_put,
.vcpu_blocking = svm_vcpu_blocking,
.vcpu_unblocking = svm_vcpu_unblocking,
.update_bp_intercept = update_bp_intercept,
.get_msr = svm_get_msr,