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

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>
Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20230405003133.419177-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index ec22101..09eb378 100644 (file)
--- 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 2e2d08d..ded0bd6 100644 (file)
--- 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 55d7fcb..ff127d3 100644 (file)
--- 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 7654be4..a7adbac 100644 (file)
--- 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);
 }