diff options
| author | Marcelo Tosatti <mtosatti@redhat.com> | 2009-12-23 14:35:21 -0200 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2010-03-01 12:35:44 -0300 |
| commit | bc6678a33d9b952981a8e44a4f876c3ad64ca4d8 (patch) | |
| tree | e26027179eb0d76f234509145a395dd6e5910074 /arch/x86/kvm/mmu.c | |
| parent | 3ad26d8139a82b0510b1e0435ee82ae461d33401 (diff) | |
KVM: introduce kvm->srcu and convert kvm_set_memory_region to SRCU update
Use two steps for memslot deletion: mark the slot invalid (which stops
instantiation of new shadow pages for that slot, but allows destruction),
then instantiate the new empty slot.
Also simplifies kvm_handle_hva locking.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/kvm/mmu.c')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 28 |
1 files changed, 14 insertions, 14 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 81f84d326a8..f8bf42a2599 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -29,6 +29,7 @@ #include <linux/swap.h> #include <linux/hugetlb.h> #include <linux/compiler.h> +#include <linux/srcu.h> #include <asm/page.h> #include <asm/cmpxchg.h> @@ -807,21 +808,15 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, { int i, j; int retval = 0; - struct kvm_memslots *slots = kvm->memslots; + struct kvm_memslots *slots; + + slots = rcu_dereference(kvm->memslots); - /* - * If mmap_sem isn't taken, we can look the memslots with only - * the mmu_lock by skipping over the slots with userspace_addr == 0. - */ for (i = 0; i < slots->nmemslots; i++) { struct kvm_memory_slot *memslot = &slots->memslots[i]; unsigned long start = memslot->userspace_addr; unsigned long end; - /* mmu_lock protects userspace_addr */ - if (!start) - continue; - end = start + (memslot->npages << PAGE_SHIFT); if (hva >= start && hva < end) { gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT; @@ -1617,7 +1612,7 @@ static void mmu_unshadow(struct kvm *kvm, gfn_t gfn) static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn) { - int slot = memslot_id(kvm, gfn_to_memslot(kvm, gfn)); + int slot = memslot_id(kvm, gfn); struct kvm_mmu_page *sp = page_header(__pa(pte)); __set_bit(slot, sp->slot_bitmap); @@ -3021,9 +3016,11 @@ unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm) int i; unsigned int nr_mmu_pages; unsigned int nr_pages = 0; + struct kvm_memslots *slots; - for (i = 0; i < kvm->memslots->nmemslots; i++) - nr_pages += kvm->memslots->memslots[i].npages; + slots = rcu_dereference(kvm->memslots); + for (i = 0; i < slots->nmemslots; i++) + nr_pages += slots->memslots[i].npages; nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000; nr_mmu_pages = max(nr_mmu_pages, @@ -3293,10 +3290,12 @@ static void audit_mappings(struct kvm_vcpu *vcpu) static int count_rmaps(struct kvm_vcpu *vcpu) { int nmaps = 0; - int i, j, k; + int i, j, k, idx; + idx = srcu_read_lock(&kvm->srcu); + slots = rcu_dereference(kvm->memslots); for (i = 0; i < KVM_MEMORY_SLOTS; ++i) { - struct kvm_memory_slot *m = &vcpu->kvm->memslots->memslots[i]; + struct kvm_memory_slot *m = &slots->memslots[i]; struct kvm_rmap_desc *d; for (j = 0; j < m->npages; ++j) { @@ -3319,6 +3318,7 @@ static int count_rmaps(struct kvm_vcpu *vcpu) } } } + srcu_read_unlock(&kvm->srcu, idx); return nmaps; } |