[PATCH 1/3] KVM: only retrieve memslots once when initializing cache

From: Paolo Bonzini
Date: Wed Feb 15 2017 - 17:02:14 EST


This will make it a bit simpler to handle multiple address spaces
in gfn_to_hva_cache.

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
virt/kvm/kvm_main.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 482612b4e496..e21bac7ed5d3 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1937,10 +1937,10 @@ int kvm_vcpu_write_guest(struct kvm_vcpu *vcpu, gpa_t gpa, const void *data,
}
EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest);

-int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
- gpa_t gpa, unsigned long len)
+static int __kvm_gfn_to_hva_cache_init(struct kvm_memslots *slots,
+ struct gfn_to_hva_cache *ghc,
+ gpa_t gpa, unsigned long len)
{
- struct kvm_memslots *slots = kvm_memslots(kvm);
int offset = offset_in_page(gpa);
gfn_t start_gfn = gpa >> PAGE_SHIFT;
gfn_t end_gfn = (gpa + len - 1) >> PAGE_SHIFT;
@@ -1950,7 +1950,7 @@ int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
ghc->gpa = gpa;
ghc->generation = slots->generation;
ghc->len = len;
- ghc->memslot = gfn_to_memslot(kvm, start_gfn);
+ ghc->memslot = __gfn_to_memslot(slots, start_gfn);
ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, NULL);
if (!kvm_is_error_hva(ghc->hva) && nr_pages_needed <= 1) {
ghc->hva += offset;
@@ -1960,7 +1960,7 @@ int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
* verify that the entire region is valid here.
*/
while (start_gfn <= end_gfn) {
- ghc->memslot = gfn_to_memslot(kvm, start_gfn);
+ ghc->memslot = __gfn_to_memslot(slots, start_gfn);
ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn,
&nr_pages_avail);
if (kvm_is_error_hva(ghc->hva))
@@ -1972,6 +1972,13 @@ int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
}
return 0;
}
+
+int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
+ gpa_t gpa, unsigned long len)
+{
+ struct kvm_memslots *slots = kvm_memslots(kvm);
+ return __kvm_gfn_to_hva_cache_init(slots, ghc, gpa, len);
+}
EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init);

int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
@@ -1984,7 +1991,7 @@ int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
BUG_ON(len + offset > ghc->len);

if (slots->generation != ghc->generation)
- kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa, ghc->len);
+ __kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len);

if (unlikely(!ghc->memslot))
return kvm_write_guest(kvm, gpa, data, len);
@@ -2017,7 +2024,7 @@ int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
BUG_ON(len > ghc->len);

if (slots->generation != ghc->generation)
- kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa, ghc->len);
+ __kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len);

if (unlikely(!ghc->memslot))
return kvm_read_guest(kvm, ghc->gpa, data, len);
--
1.8.3.1