2022-05-25 16:48:36

by Vitaly Kuznetsov

Subject: [PATCH v4 02/37] KVM: x86: hyper-v: Resurrect dedicated KVM_REQ_HV_TLB_FLUSH flag

In preparation to implementing fine-grained Hyper-V TLB flush and
L2 TLB flush, resurrect dedicated KVM_REQ_HV_TLB_FLUSH request bit. As
KVM_REQ_TLB_FLUSH_GUEST/KVM_REQ_TLB_FLUSH_GUEST/KVM_REQ_TLB_FLUSH_CURRENT
are stronger operations, clear KVM_REQ_HV_TLB_FLUSH request in
kvm_service_local_tlb_flush_requests() when any of these were also
requested.

No (real) functional change intended.

Signed-off-by: Vitaly Kuznetsov <[email protected]>
---
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/kvm/hyperv.c | 4 ++--
arch/x86/kvm/x86.c | 10 ++++++++--
3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 151880cfab9e..92509ee6ae1b 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -105,6 +105,8 @@
KVM_ARCH_REQ_FLAGS(30, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
#define KVM_REQ_MMU_FREE_OBSOLETE_ROOTS \
KVM_ARCH_REQ_FLAGS(31, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
+#define KVM_REQ_HV_TLB_FLUSH \
+ KVM_ARCH_REQ_FLAGS(32, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)

#define CR0_RESERVED_BITS \
(~(unsigned long)(X86_CR0_PE | X86_CR0_MP | X86_CR0_EM | X86_CR0_TS \
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 46f9dfb60469..b402ad059eb9 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1876,11 +1876,11 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
* analyze it here, flush TLB regardless of the specified address space.
*/
if (all_cpus) {
- kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH_GUEST);
+ kvm_make_all_cpus_request(kvm, KVM_REQ_HV_TLB_FLUSH);
} else {
sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask, vcpu_mask);

- kvm_make_vcpus_request_mask(kvm, KVM_REQ_TLB_FLUSH_GUEST, vcpu_mask);
+ kvm_make_vcpus_request_mask(kvm, KVM_REQ_HV_TLB_FLUSH, vcpu_mask);
}

ret_success:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 891507b2eca5..f98503431f8d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3363,11 +3363,17 @@ static inline void kvm_vcpu_flush_tlb_current(struct kvm_vcpu *vcpu)
*/
void kvm_service_local_tlb_flush_requests(struct kvm_vcpu *vcpu)
{
- if (kvm_check_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu))
+ if (kvm_check_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu)) {
kvm_vcpu_flush_tlb_current(vcpu);
+ kvm_clear_request(KVM_REQ_HV_TLB_FLUSH, vcpu);
+ }

- if (kvm_check_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu))
+ if (kvm_check_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu)) {
+ kvm_vcpu_flush_tlb_guest(vcpu);
+ kvm_clear_request(KVM_REQ_HV_TLB_FLUSH, vcpu);
+ } else if (kvm_check_request(KVM_REQ_HV_TLB_FLUSH, vcpu)) {
kvm_vcpu_flush_tlb_guest(vcpu);
+ }
}
EXPORT_SYMBOL_GPL(kvm_service_local_tlb_flush_requests);

--
2.35.3

2022-05-27 17:58:47

by Yuan Yao

Subject: Re: [PATCH v4 02/37] KVM: x86: hyper-v: Resurrect dedicated KVM_REQ_HV_TLB_FLUSH flag

On Wed, May 25, 2022 at 11:00:58AM +0200, Vitaly Kuznetsov wrote:
> In preparation to implementing fine-grained Hyper-V TLB flush and
> L2 TLB flush, resurrect dedicated KVM_REQ_HV_TLB_FLUSH request bit. As
> KVM_REQ_TLB_FLUSH_GUEST/KVM_REQ_TLB_FLUSH_GUEST/KVM_REQ_TLB_FLUSH_CURRENT

Duplicated KVM_REQ_TLB_FLUSH_GUEST here ?

> are stronger operations, clear KVM_REQ_HV_TLB_FLUSH request in
> kvm_service_local_tlb_flush_requests() when any of these were also
> requested.
>
> No (real) functional change intended.
>
> Signed-off-by: Vitaly Kuznetsov <[email protected]>
> ---
> arch/x86/include/asm/kvm_host.h | 2 ++
> arch/x86/kvm/hyperv.c | 4 ++--
> arch/x86/kvm/x86.c | 10 ++++++++--
> 3 files changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 151880cfab9e..92509ee6ae1b 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -105,6 +105,8 @@
> KVM_ARCH_REQ_FLAGS(30, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
> #define KVM_REQ_MMU_FREE_OBSOLETE_ROOTS \
> KVM_ARCH_REQ_FLAGS(31, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
> +#define KVM_REQ_HV_TLB_FLUSH \
> + KVM_ARCH_REQ_FLAGS(32, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
>
> #define CR0_RESERVED_BITS \
> (~(unsigned long)(X86_CR0_PE | X86_CR0_MP | X86_CR0_EM | X86_CR0_TS \
> diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
> index 46f9dfb60469..b402ad059eb9 100644
> --- a/arch/x86/kvm/hyperv.c
> +++ b/arch/x86/kvm/hyperv.c
> @@ -1876,11 +1876,11 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
> * analyze it here, flush TLB regardless of the specified address space.
> */
> if (all_cpus) {
> - kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH_GUEST);
> + kvm_make_all_cpus_request(kvm, KVM_REQ_HV_TLB_FLUSH);
> } else {
> sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask, vcpu_mask);
>
> - kvm_make_vcpus_request_mask(kvm, KVM_REQ_TLB_FLUSH_GUEST, vcpu_mask);
> + kvm_make_vcpus_request_mask(kvm, KVM_REQ_HV_TLB_FLUSH, vcpu_mask);
> }
>
> ret_success:
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 891507b2eca5..f98503431f8d 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -3363,11 +3363,17 @@ static inline void kvm_vcpu_flush_tlb_current(struct kvm_vcpu *vcpu)
> */
> void kvm_service_local_tlb_flush_requests(struct kvm_vcpu *vcpu)
> {
> - if (kvm_check_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu))
> + if (kvm_check_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu)) {
> kvm_vcpu_flush_tlb_current(vcpu);
> + kvm_clear_request(KVM_REQ_HV_TLB_FLUSH, vcpu);
> + }
>
> - if (kvm_check_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu))
> + if (kvm_check_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu)) {
> + kvm_vcpu_flush_tlb_guest(vcpu);
> + kvm_clear_request(KVM_REQ_HV_TLB_FLUSH, vcpu);
> + } else if (kvm_check_request(KVM_REQ_HV_TLB_FLUSH, vcpu)) {
> kvm_vcpu_flush_tlb_guest(vcpu);
> + }
> }
> EXPORT_SYMBOL_GPL(kvm_service_local_tlb_flush_requests);
>
> --
> 2.35.3
>