hv: TLFS: Add tsc_offset support for reference time

TLFS spec defines that when a VM is created, the value of
HV_X64_MSR_TIME_REF_COUNT is set to zero. Now tsc_offset is not
supported properly, so guest get a drifted reference time.

This patch implements tsc_offset. tsc_scale and tsc_offset
are calculated when a VM is launched and are saved in
struct acrn_hyperv of struct acrn_vm.

Tracked-On: #5956
Signed-off-by: Jian Jun Chen <jian.jun.chen@intel.com>
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
This commit is contained in:
Jian Jun Chen 2019-12-20 10:07:27 +08:00 committed by wenlingz
parent b4312efbd7
commit 31b8b698ce
3 changed files with 45 additions and 43 deletions

View File

@ -56,41 +56,11 @@ u64_mul_u64_shr64(uint64_t a, uint64_t b)
return ret;
}
static inline void
hyperv_get_tsc_scale_offset(struct acrn_vm *vm, uint64_t *scale, uint64_t *offset)
{
if (vm->arch_vm.hyperv.tsc_scale == 0UL) {
/*
* The partition reference time is computed by the following formula:
* ReferenceTime = ((VirtualTsc * TscScale) >> 64) + TscOffset
* ReferenceTime is in 100ns units
*
* ReferenceTime =
* VirtualTsc / (get_tsc_khz() * 1000) * 1000000000 / 100
* + TscOffset
*/
uint64_t ret, khz = get_tsc_khz();
/* ret = (10000U << 64U) / get_tsc_khz() */
ret = u64_shl64_div_u64(10000U, khz);
dev_dbg(DBG_LEVEL_HYPERV, "%s, ret = 0x%lx", __func__, ret);
vm->arch_vm.hyperv.tsc_scale = ret;
vm->arch_vm.hyperv.tsc_offset = 0UL;
}
*scale = vm->arch_vm.hyperv.tsc_scale;
*offset = vm->arch_vm.hyperv.tsc_offset;
}
static void
hyperv_setup_tsc_page(const struct acrn_vcpu *vcpu, uint64_t val)
{
union hyperv_ref_tsc_page_msr *ref_tsc_page = &vcpu->vm->arch_vm.hyperv.ref_tsc_page;
struct HV_REFERENCE_TSC_PAGE *p;
uint64_t tsc_scale, tsc_offset;
uint32_t tsc_seq;
ref_tsc_page->val64 = val;
@ -98,10 +68,9 @@ hyperv_setup_tsc_page(const struct acrn_vcpu *vcpu, uint64_t val)
if (ref_tsc_page->enabled == 1U) {
p = (struct HV_REFERENCE_TSC_PAGE *)gpa2hva(vcpu->vm, ref_tsc_page->gpfn << PAGE_SHIFT);
if (p != NULL) {
hyperv_get_tsc_scale_offset(vcpu->vm, &tsc_scale, &tsc_offset);
stac();
p->tsc_scale = tsc_scale;
p->tsc_offset = tsc_offset;
p->tsc_scale = vcpu->vm->arch_vm.hyperv.tsc_scale;
p->tsc_offset = vcpu->vm->arch_vm.hyperv.tsc_offset;
cpu_write_memory_barrier();
tsc_seq = p->tsc_sequence + 1U;
if ((tsc_seq == 0xFFFFFFFFU) || (tsc_seq == 0U)) {
@ -114,19 +83,19 @@ hyperv_setup_tsc_page(const struct acrn_vcpu *vcpu, uint64_t val)
}
static inline uint64_t
hyperv_get_ref_count(struct acrn_vm *vm)
hyperv_scale_tsc(uint64_t scale)
{
uint64_t tsc, tsc_scale, tsc_offset, ret;
uint64_t tsc;
/* currently only "use tsc offsetting" is set to 1 */
tsc = rdtsc() + exec_vmread64(VMX_TSC_OFFSET_FULL);
hyperv_get_tsc_scale_offset(vm, &tsc_scale, &tsc_offset);
return u64_mul_u64_shr64(tsc, scale);
}
/* ret = ((tsc * tsc_scale) >> 64) + tsc_offset */
ret = u64_mul_u64_shr64(tsc, tsc_scale) + tsc_offset;
return ret;
static inline uint64_t
hyperv_get_ReferenceTime(struct acrn_vm *vm)
{
return hyperv_scale_tsc(vm->arch_vm.hyperv.tsc_scale) - vm->arch_vm.hyperv.tsc_offset;
}
static void
@ -227,7 +196,7 @@ hyperv_rdmsr(struct acrn_vcpu *vcpu, uint32_t msr, uint64_t *rval)
*rval = vcpu->vcpu_id;
break;
case HV_X64_MSR_TIME_REF_COUNT:
*rval = hyperv_get_ref_count(vcpu->vm);
*rval = hyperv_get_ReferenceTime(vcpu->vm);
break;
case HV_X64_MSR_REFERENCE_TSC:
*rval = vcpu->vm->arch_vm.hyperv.ref_tsc_page.val64;
@ -244,6 +213,33 @@ hyperv_rdmsr(struct acrn_vcpu *vcpu, uint32_t msr, uint64_t *rval)
return ret;
}
void
hyperv_init_time(struct acrn_vm *vm)
{
uint64_t tsc_scale, tsc_khz = get_tsc_khz();
uint64_t tsc_offset;
/*
* The partition reference time is computed by the following formula:
* ReferenceTime = ((VirtualTsc * TscScale) >> 64) + TscOffset
* ReferenceTime is in 100ns units
*
* ReferenceTime =
* VirtualTsc / (get_tsc_khz() * 1000) * 1000000000 / 100
* + TscOffset
*
* TscScale = (10000U << 64U) / get_tsc_khz()
*/
tsc_scale = u64_shl64_div_u64(10000U, tsc_khz);
tsc_offset = hyperv_scale_tsc(tsc_scale);
vm->arch_vm.hyperv.tsc_scale = tsc_scale;
vm->arch_vm.hyperv.tsc_offset = tsc_offset;
dev_dbg(DBG_LEVEL_HYPERV, "%s, tsc_scale = 0x%lx, tsc_offset = %ld",
__func__, tsc_scale, tsc_offset);
}
void
hyperv_init_vcpuid_entry(uint32_t leaf, uint32_t subleaf, uint32_t flags,
struct vcpuid_entry *entry)

View File

@ -643,6 +643,12 @@ int32_t run_vcpu(struct acrn_vcpu *vcpu)
*/
flush_vpid_global();
#ifdef CONFIG_HYPERV_ENABLED
if (is_vcpu_bsp(vcpu)) {
hyperv_init_time(vcpu->vm);
}
#endif
/* Set vcpu launched */
vcpu->launched = true;

View File

@ -59,7 +59,7 @@ struct acrn_hyperv {
int32_t hyperv_wrmsr(struct acrn_vcpu *vcpu, uint32_t msr, uint64_t wval);
int32_t hyperv_rdmsr(struct acrn_vcpu *vcpu, uint32_t msr, uint64_t *rval);
void hyperv_init_time(struct acrn_vm *vm);
void hyperv_init_vcpuid_entry(uint32_t leaf, uint32_t subleaf, uint32_t flags,
struct vcpuid_entry *entry);
#endif