[PATCH 0/2] KVM: x86: More cleanups for Hyper-V range flushing

[PATCH 0/2] KVM: x86: More cleanups for Hyper-V range flushing

[Sean Christopherson]

More cleanups of the code related to Hyper-V's range-based TLB flushing.
David's series got most of the names, but there are a few more that can
be converted (patch 1).  On top of that, having Hyper-V fill its struct
provides a decent improvement to code generation, and IMO yields a better
API (patch 2).

Sean Christopherson (2):
  KVM: x86: Rename Hyper-V remote TLB hooks to match established scheme
  KVM: x86/mmu: Move filling of Hyper-V's TLB range struct into Hyper-V
    code

 arch/x86/include/asm/kvm-x86-ops.h |  4 ++--
 arch/x86/include/asm/kvm_host.h    | 15 +++++---------
 arch/x86/kvm/kvm_onhyperv.c        | 33 ++++++++++++++++++++++--------
 arch/x86/kvm/kvm_onhyperv.h        |  5 ++---
 arch/x86/kvm/mmu/mmu.c             | 18 +++++++---------
 arch/x86/kvm/svm/svm_onhyperv.h    |  5 ++---
 arch/x86/kvm/vmx/vmx.c             |  5 ++---
 7 files changed, 44 insertions(+), 41 deletions(-)


base-commit: 50f13998451effea5c5fdc70fe576f8b435d6224
-- 
2.40.0.348.gf938b09366-goog

[PATCH 1/2] KVM: x86: Rename Hyper-V remote TLB hooks to match established scheme

[Sean Christopherson]

Rename the Hyper-V hooks for TLB flushing to match the naming scheme used
by all the other TLB flushing hooks, e.g. in kvm_x86_ops, vendor code,
arch hooks from common code, etc.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/include/asm/kvm-x86-ops.h |  4 ++--
 arch/x86/include/asm/kvm_host.h    | 10 +++++-----
 arch/x86/kvm/kvm_onhyperv.c        | 13 ++++++-------
 arch/x86/kvm/kvm_onhyperv.h        |  5 ++---
 arch/x86/kvm/mmu/mmu.c             | 12 ++++++------
 arch/x86/kvm/svm/svm_onhyperv.h    |  5 ++---
 arch/x86/kvm/vmx/vmx.c             |  5 ++---
 7 files changed, 25 insertions(+), 29 deletions(-)

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index 8dc345cc6318..430ca22170e0 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -54,8 +54,8 @@ KVM_X86_OP(set_rflags)
 KVM_X86_OP(get_if_flag)
 KVM_X86_OP(flush_tlb_all)
 KVM_X86_OP(flush_tlb_current)
-KVM_X86_OP_OPTIONAL(tlb_remote_flush)
-KVM_X86_OP_OPTIONAL(tlb_remote_flush_with_range)
+KVM_X86_OP_OPTIONAL(flush_remote_tlbs)
+KVM_X86_OP_OPTIONAL(flush_remote_tlbs_range)
 KVM_X86_OP(flush_tlb_gva)
 KVM_X86_OP(flush_tlb_guest)
 KVM_X86_OP(vcpu_pre_run)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 991296a2f807..ec22101410ee 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1588,9 +1588,9 @@ struct kvm_x86_ops {
 
 	void (*flush_tlb_all)(struct kvm_vcpu *vcpu);
 	void (*flush_tlb_current)(struct kvm_vcpu *vcpu);
-	int  (*tlb_remote_flush)(struct kvm *kvm);
-	int  (*tlb_remote_flush_with_range)(struct kvm *kvm,
-			struct kvm_tlb_range *range);
+	int  (*flush_remote_tlbs)(struct kvm *kvm);
+	int  (*flush_remote_tlbs_range)(struct kvm *kvm,
+					struct kvm_tlb_range *range);
 
 	/*
 	 * Flush any TLB entries associated with the given GVA.
@@ -1794,8 +1794,8 @@ void kvm_arch_free_vm(struct kvm *kvm);
 #define __KVM_HAVE_ARCH_FLUSH_REMOTE_TLB
 static inline int kvm_arch_flush_remote_tlb(struct kvm *kvm)
 {
-	if (kvm_x86_ops.tlb_remote_flush &&
-	    !static_call(kvm_x86_tlb_remote_flush)(kvm))
+	if (kvm_x86_ops.flush_remote_tlbs &&
+	    !static_call(kvm_x86_flush_remote_tlbs)(kvm))
 		return 0;
 	else
 		return -ENOTSUPP;
diff --git a/arch/x86/kvm/kvm_onhyperv.c b/arch/x86/kvm/kvm_onhyperv.c
index 482d6639ef88..2e2d08da8a3f 100644
--- a/arch/x86/kvm/kvm_onhyperv.c
+++ b/arch/x86/kvm/kvm_onhyperv.c
@@ -29,8 +29,7 @@ static inline int hv_remote_flush_root_tdp(hpa_t root_tdp,
 		return hyperv_flush_guest_mapping(root_tdp);
 }
 
-int hv_remote_flush_tlb_with_range(struct kvm *kvm,
-		struct kvm_tlb_range *range)
+int hv_flush_remote_tlbs_range(struct kvm *kvm, struct kvm_tlb_range *range)
 {
 	struct kvm_arch *kvm_arch = &kvm->arch;
 	struct kvm_vcpu *vcpu;
@@ -86,19 +85,19 @@ int hv_remote_flush_tlb_with_range(struct kvm *kvm,
 	spin_unlock(&kvm_arch->hv_root_tdp_lock);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(hv_remote_flush_tlb_with_range);
+EXPORT_SYMBOL_GPL(hv_flush_remote_tlbs_range);
 
-int hv_remote_flush_tlb(struct kvm *kvm)
+int hv_flush_remote_tlbs(struct kvm *kvm)
 {
-	return hv_remote_flush_tlb_with_range(kvm, NULL);
+	return hv_flush_remote_tlbs_range(kvm, NULL);
 }
-EXPORT_SYMBOL_GPL(hv_remote_flush_tlb);
+EXPORT_SYMBOL_GPL(hv_flush_remote_tlbs);
 
 void hv_track_root_tdp(struct kvm_vcpu *vcpu, hpa_t root_tdp)
 {
 	struct kvm_arch *kvm_arch = &vcpu->kvm->arch;
 
-	if (kvm_x86_ops.tlb_remote_flush == hv_remote_flush_tlb) {
+	if (kvm_x86_ops.flush_remote_tlbs == hv_flush_remote_tlbs) {
 		spin_lock(&kvm_arch->hv_root_tdp_lock);
 		vcpu->arch.hv_root_tdp = root_tdp;
 		if (root_tdp != kvm_arch->hv_root_tdp)
diff --git a/arch/x86/kvm/kvm_onhyperv.h b/arch/x86/kvm/kvm_onhyperv.h
index 287e98ef9df3..55d7fcb84cc1 100644
--- a/arch/x86/kvm/kvm_onhyperv.h
+++ b/arch/x86/kvm/kvm_onhyperv.h
@@ -7,9 +7,8 @@
 #define __ARCH_X86_KVM_KVM_ONHYPERV_H__
 
 #if IS_ENABLED(CONFIG_HYPERV)
-int hv_remote_flush_tlb_with_range(struct kvm *kvm,
-		struct kvm_tlb_range *range);
-int hv_remote_flush_tlb(struct kvm *kvm);
+int hv_flush_remote_tlbs_range(struct kvm *kvm, struct kvm_tlb_range *range);
+int hv_flush_remote_tlbs(struct kvm *kvm);
 void hv_track_root_tdp(struct kvm_vcpu *vcpu, hpa_t root_tdp);
 #else /* !CONFIG_HYPERV */
 static inline void hv_track_root_tdp(struct kvm_vcpu *vcpu, hpa_t root_tdp)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 4c874d4ec68f..7654be48ff69 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -270,9 +270,9 @@ static inline unsigned long kvm_mmu_get_guest_pgd(struct kvm_vcpu *vcpu,
 	return mmu->get_guest_pgd(vcpu);
 }
 
-static inline bool kvm_available_flush_tlb_with_range(void)
+static inline bool kvm_available_flush_remote_tlbs_range(void)
 {
-	return kvm_x86_ops.tlb_remote_flush_with_range;
+	return kvm_x86_ops.flush_remote_tlbs_range;
 }
 
 void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn,
@@ -284,8 +284,8 @@ void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn,
 	range.start_gfn = start_gfn;
 	range.pages = nr_pages;
 
-	if (kvm_x86_ops.tlb_remote_flush_with_range)
-		ret = static_call(kvm_x86_tlb_remote_flush_with_range)(kvm, &range);
+	if (kvm_x86_ops.flush_remote_tlbs_range)
+		ret = static_call(kvm_x86_flush_remote_tlbs_range)(kvm, &range);
 
 	if (ret)
 		kvm_flush_remote_tlbs(kvm);
@@ -1498,7 +1498,7 @@ static bool kvm_set_pte_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
 		}
 	}
 
-	if (need_flush && kvm_available_flush_tlb_with_range()) {
+	if (need_flush && kvm_available_flush_remote_tlbs_range()) {
 		kvm_flush_remote_tlbs_gfn(kvm, gfn, level);
 		return false;
 	}
@@ -6623,7 +6623,7 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm,
 							       PG_LEVEL_NUM)) {
 			kvm_zap_one_rmap_spte(kvm, rmap_head, sptep);
 
-			if (kvm_available_flush_tlb_with_range())
+			if (kvm_available_flush_remote_tlbs_range())
 				kvm_flush_remote_tlbs_sptep(kvm, sptep);
 			else
 				need_tlb_flush = 1;
diff --git a/arch/x86/kvm/svm/svm_onhyperv.h b/arch/x86/kvm/svm/svm_onhyperv.h
index cff838f15db5..823001033539 100644
--- a/arch/x86/kvm/svm/svm_onhyperv.h
+++ b/arch/x86/kvm/svm/svm_onhyperv.h
@@ -35,9 +35,8 @@ static inline __init void svm_hv_hardware_setup(void)
 	if (npt_enabled &&
 	    ms_hyperv.nested_features & HV_X64_NESTED_ENLIGHTENED_TLB) {
 		pr_info(KBUILD_MODNAME ": Hyper-V enlightened NPT TLB flush enabled\n");
-		svm_x86_ops.tlb_remote_flush = hv_remote_flush_tlb;
-		svm_x86_ops.tlb_remote_flush_with_range =
-				hv_remote_flush_tlb_with_range;
+		svm_x86_ops.flush_remote_tlbs = hv_flush_remote_tlbs;
+		svm_x86_ops.flush_remote_tlbs_range = hv_flush_remote_tlbs_range;
 	}
 
 	if (ms_hyperv.nested_features & HV_X64_NESTED_DIRECT_FLUSH) {
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index d7bf14abdba1..8031bded75cc 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -8432,9 +8432,8 @@ static __init int hardware_setup(void)
 #if IS_ENABLED(CONFIG_HYPERV)
 	if (ms_hyperv.nested_features & HV_X64_NESTED_GUEST_MAPPING_FLUSH
 	    && enable_ept) {
-		vmx_x86_ops.tlb_remote_flush = hv_remote_flush_tlb;
-		vmx_x86_ops.tlb_remote_flush_with_range =
-				hv_remote_flush_tlb_with_range;
+		vmx_x86_ops.flush_remote_tlbs = hv_flush_remote_tlbs;
+		vmx_x86_ops.flush_remote_tlbs_range = hv_flush_remote_tlbs_range;
 	}
 #endif
 
-- 
2.40.0.348.gf938b09366-goog

[PATCH 2/2] KVM: x86/mmu: Move filling of Hyper-V's TLB range struct into Hyper-V code

[Sean Christopherson]

Refactor Hyper-V's range-based TLB flushing API to take a gfn+nr_pages
pair instead of a struct, and bury said struct in Hyper-V specific code.

Passing along two params generates much better code for the common case
where KVM is _not_ running on Hyper-V, as forwarding the flush on to
Hyper-V's hv_flush_remote_tlbs_range() from kvm_flush_remote_tlbs_range()
becomes a tail call.

Cc: David Matlack <dmatlack@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/include/asm/kvm_host.h |  9 ++-------
 arch/x86/kvm/kvm_onhyperv.c     | 24 ++++++++++++++++++++----
 arch/x86/kvm/kvm_onhyperv.h     |  2 +-
 arch/x86/kvm/mmu/mmu.c          |  8 ++------
 4 files changed, 25 insertions(+), 18 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index ec22101410ee..09eb37853cb1 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -482,11 +482,6 @@ struct kvm_mmu {
 	u64 pdptrs[4]; /* pae */
 };
 
-struct kvm_tlb_range {
-	u64 start_gfn;
-	u64 pages;
-};
-
 enum pmc_type {
 	KVM_PMC_GP = 0,
 	KVM_PMC_FIXED,
@@ -1589,8 +1584,8 @@ struct kvm_x86_ops {
 	void (*flush_tlb_all)(struct kvm_vcpu *vcpu);
 	void (*flush_tlb_current)(struct kvm_vcpu *vcpu);
 	int  (*flush_remote_tlbs)(struct kvm *kvm);
-	int  (*flush_remote_tlbs_range)(struct kvm *kvm,
-					struct kvm_tlb_range *range);
+	int  (*flush_remote_tlbs_range)(struct kvm *kvm, gfn_t gfn,
+					gfn_t nr_pages);
 
 	/*
 	 * Flush any TLB entries associated with the given GVA.
diff --git a/arch/x86/kvm/kvm_onhyperv.c b/arch/x86/kvm/kvm_onhyperv.c
index 2e2d08da8a3f..ded0bd688c65 100644
--- a/arch/x86/kvm/kvm_onhyperv.c
+++ b/arch/x86/kvm/kvm_onhyperv.c
@@ -10,17 +10,22 @@
 #include "hyperv.h"
 #include "kvm_onhyperv.h"
 
+struct kvm_hv_tlb_range {
+	u64 start_gfn;
+	u64 pages;
+};
+
 static int kvm_fill_hv_flush_list_func(struct hv_guest_mapping_flush_list *flush,
 		void *data)
 {
-	struct kvm_tlb_range *range = data;
+	struct kvm_hv_tlb_range *range = data;
 
 	return hyperv_fill_flush_guest_mapping_list(flush, range->start_gfn,
 			range->pages);
 }
 
 static inline int hv_remote_flush_root_tdp(hpa_t root_tdp,
-					   struct kvm_tlb_range *range)
+					   struct kvm_hv_tlb_range *range)
 {
 	if (range)
 		return hyperv_flush_guest_mapping_range(root_tdp,
@@ -29,7 +34,8 @@ static inline int hv_remote_flush_root_tdp(hpa_t root_tdp,
 		return hyperv_flush_guest_mapping(root_tdp);
 }
 
-int hv_flush_remote_tlbs_range(struct kvm *kvm, struct kvm_tlb_range *range)
+static int __hv_flush_remote_tlbs_range(struct kvm *kvm,
+					struct kvm_hv_tlb_range *range)
 {
 	struct kvm_arch *kvm_arch = &kvm->arch;
 	struct kvm_vcpu *vcpu;
@@ -85,11 +91,21 @@ int hv_flush_remote_tlbs_range(struct kvm *kvm, struct kvm_tlb_range *range)
 	spin_unlock(&kvm_arch->hv_root_tdp_lock);
 	return ret;
 }
+
+int hv_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn, gfn_t nr_pages)
+{
+	struct kvm_hv_tlb_range range = {
+		.start_gfn = start_gfn,
+		.pages = nr_pages,
+	};
+
+	return __hv_flush_remote_tlbs_range(kvm, &range);
+}
 EXPORT_SYMBOL_GPL(hv_flush_remote_tlbs_range);
 
 int hv_flush_remote_tlbs(struct kvm *kvm)
 {
-	return hv_flush_remote_tlbs_range(kvm, NULL);
+	return __hv_flush_remote_tlbs_range(kvm, NULL);
 }
 EXPORT_SYMBOL_GPL(hv_flush_remote_tlbs);
 
diff --git a/arch/x86/kvm/kvm_onhyperv.h b/arch/x86/kvm/kvm_onhyperv.h
index 55d7fcb84cc1..ff127d313242 100644
--- a/arch/x86/kvm/kvm_onhyperv.h
+++ b/arch/x86/kvm/kvm_onhyperv.h
@@ -7,7 +7,7 @@
 #define __ARCH_X86_KVM_KVM_ONHYPERV_H__
 
 #if IS_ENABLED(CONFIG_HYPERV)
-int hv_flush_remote_tlbs_range(struct kvm *kvm, struct kvm_tlb_range *range);
+int hv_flush_remote_tlbs_range(struct kvm *kvm, gfn_t gfn, gfn_t nr_pages);
 int hv_flush_remote_tlbs(struct kvm *kvm);
 void hv_track_root_tdp(struct kvm_vcpu *vcpu, hpa_t root_tdp);
 #else /* !CONFIG_HYPERV */
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 7654be48ff69..a7adbac0855c 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -278,15 +278,11 @@ static inline bool kvm_available_flush_remote_tlbs_range(void)
 void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn,
 				 gfn_t nr_pages)
 {
-	struct kvm_tlb_range range;
 	int ret = -EOPNOTSUPP;
 
-	range.start_gfn = start_gfn;
-	range.pages = nr_pages;
-
 	if (kvm_x86_ops.flush_remote_tlbs_range)
-		ret = static_call(kvm_x86_flush_remote_tlbs_range)(kvm, &range);
-
+		ret = static_call(kvm_x86_flush_remote_tlbs_range)(kvm, start_gfn,
+								   nr_pages);
 	if (ret)
 		kvm_flush_remote_tlbs(kvm);
 }
-- 
2.40.0.348.gf938b09366-goog

Re: [PATCH 0/2] KVM: x86: More cleanups for Hyper-V range flushing

[Vitaly Kuznetsov]

Sean Christopherson <seanjc@google.com> writes:

> More cleanups of the code related to Hyper-V's range-based TLB flushing.
> David's series got most of the names, but there are a few more that can
> be converted (patch 1).  On top of that, having Hyper-V fill its struct
> provides a decent improvement to code generation, and IMO yields a better
> API (patch 2).
>
> Sean Christopherson (2):
>   KVM: x86: Rename Hyper-V remote TLB hooks to match established scheme
>   KVM: x86/mmu: Move filling of Hyper-V's TLB range struct into Hyper-V
>     code
>

For the series:
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>

-- 
Vitaly

Re: [PATCH 0/2] KVM: x86: More cleanups for Hyper-V range flushing

[David Matlack]

On Tue, Apr 04, 2023 at 05:31:31PM -0700, Sean Christopherson wrote:
> More cleanups of the code related to Hyper-V's range-based TLB flushing.
> David's series got most of the names, but there are a few more that can
> be converted (patch 1).  On top of that, having Hyper-V fill its struct
> provides a decent improvement to code generation, and IMO yields a better
> API (patch 2).

Reviewed-by: David Matlack <dmatlack@google.com>

Re: [PATCH 0/2] KVM: x86: More cleanups for Hyper-V range flushing

[Sean Christopherson]

On Tue, 04 Apr 2023 17:31:31 -0700, Sean Christopherson wrote:
> More cleanups of the code related to Hyper-V's range-based TLB flushing.
> David's series got most of the names, but there are a few more that can
> be converted (patch 1).  On top of that, having Hyper-V fill its struct
> provides a decent improvement to code generation, and IMO yields a better
> API (patch 2).
> 
> Sean Christopherson (2):
>   KVM: x86: Rename Hyper-V remote TLB hooks to match established scheme
>   KVM: x86/mmu: Move filling of Hyper-V's TLB range struct into Hyper-V
>     code
> 
> [...]

Applied to kvm-x86 mmu, thanks!

[1/2] KVM: x86: Rename Hyper-V remote TLB hooks to match established scheme
      https://github.com/kvm-x86/linux/commit/8a1300ff9518
[2/2] KVM: x86/mmu: Move filling of Hyper-V's TLB range struct into Hyper-V code
      https://github.com/kvm-x86/linux/commit/9ed3bf411226

--
https://github.com/kvm-x86/linux/tree/next
https://github.com/kvm-x86/linux/tree/fixes