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authorAvi Kivity <avi@qumranet.com>2007-01-06 03:36:44 +0300
committerLinus Torvalds <torvalds@woody.osdl.org>2007-01-06 10:55:25 +0300
commitda4a00f002239f72b0d7d0eeaa3b60100e2b1438 (patch)
tree7c7e72ea1fd48025c029429b413e127a3a580c10
parent815af8d42ee3f844c0ceaf2104bd9c6a0bb1e26c (diff)
downloadlinux-sunxi-da4a00f002239f72b0d7d0eeaa3b60100e2b1438.tar.xz
[PATCH] KVM: MMU: Support emulated writes into RAM
As the mmu write protects guest page table, we emulate those writes. Since they are not mmio, there is no need to go to userspace to perform them. So, perform the writes in the kernel if possible, and notify the mmu about them so it can take the approriate action. Signed-off-by: Avi Kivity <avi@qumranet.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--drivers/kvm/kvm.h3
-rw-r--r--drivers/kvm/kvm_main.c24
-rw-r--r--drivers/kvm/mmu.c9
3 files changed, 36 insertions, 0 deletions
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 58b9deb0bc0e..b7068ecd7765 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -448,6 +448,9 @@ int kvm_write_guest(struct kvm_vcpu *vcpu,
unsigned long segment_base(u16 selector);
+void kvm_mmu_pre_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes);
+void kvm_mmu_post_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes);
+
static inline struct page *_gfn_to_page(struct kvm *kvm, gfn_t gfn)
{
struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 68e121eeccbc..047f6f6ed3f6 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -877,6 +877,27 @@ static int emulator_read_emulated(unsigned long addr,
}
}
+static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
+ unsigned long val, int bytes)
+{
+ struct kvm_memory_slot *m;
+ struct page *page;
+ void *virt;
+
+ if (((gpa + bytes - 1) >> PAGE_SHIFT) != (gpa >> PAGE_SHIFT))
+ return 0;
+ m = gfn_to_memslot(vcpu->kvm, gpa >> PAGE_SHIFT);
+ if (!m)
+ return 0;
+ page = gfn_to_page(m, gpa >> PAGE_SHIFT);
+ kvm_mmu_pre_write(vcpu, gpa, bytes);
+ virt = kmap_atomic(page, KM_USER0);
+ memcpy(virt + offset_in_page(gpa), &val, bytes);
+ kunmap_atomic(virt, KM_USER0);
+ kvm_mmu_post_write(vcpu, gpa, bytes);
+ return 1;
+}
+
static int emulator_write_emulated(unsigned long addr,
unsigned long val,
unsigned int bytes,
@@ -888,6 +909,9 @@ static int emulator_write_emulated(unsigned long addr,
if (gpa == UNMAPPED_GVA)
return X86EMUL_PROPAGATE_FAULT;
+ if (emulator_write_phys(vcpu, gpa, val, bytes))
+ return X86EMUL_CONTINUE;
+
vcpu->mmio_needed = 1;
vcpu->mmio_phys_addr = gpa;
vcpu->mmio_size = bytes;
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index ceae25bfd4b5..bce7eb21f739 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -956,6 +956,15 @@ int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
return init_kvm_mmu(vcpu);
}
+void kvm_mmu_pre_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes)
+{
+ pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes);
+}
+
+void kvm_mmu_post_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes)
+{
+}
+
static void free_mmu_pages(struct kvm_vcpu *vcpu)
{
while (!list_empty(&vcpu->free_pages)) {