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Message-Id: <1198421495-31481-22-git-send-email-avi@qumranet.com>
Date: Sun, 23 Dec 2007 16:51:06 +0200
From: Avi Kivity <avi@...ranet.com>
To: linux-kernel@...r.kernel.org, kvm-devel@...ts.sourceforge.net
Cc: Izik Eidus <izik@...e1 (none) >
Subject: [PATCH 21/50] KVM: Add general accessors to read and write guest memory
From: Izik Eidus <izik@...e1.(none)>
Signed-off-by: Izik Eidus <izike@...ranet.com>
Signed-off-by: Avi Kivity <avi@...ranet.com>
---
drivers/kvm/kvm.h | 9 +++
drivers/kvm/kvm_main.c | 160 +++++++++++++++++++++++++++++++++++++++---------
drivers/kvm/vmx.c | 43 ++++++-------
3 files changed, 158 insertions(+), 54 deletions(-)
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 80cfb99..1965438 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -559,6 +559,15 @@ extern hpa_t bad_page_address;
gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn);
struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn);
+int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
+ int len);
+int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len);
+int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
+ int offset, int len);
+int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
+ unsigned long len);
+int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len);
+int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len);
struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn);
void mark_page_dirty(struct kvm *kvm, gfn_t gfn);
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index ac563fc..3d1972e 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -400,22 +400,16 @@ static int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3)
gfn_t pdpt_gfn = cr3 >> PAGE_SHIFT;
unsigned offset = ((cr3 & (PAGE_SIZE-1)) >> 5) << 2;
int i;
- u64 *pdpt;
int ret;
- struct page *page;
u64 pdpte[ARRAY_SIZE(vcpu->pdptrs)];
mutex_lock(&vcpu->kvm->lock);
- page = gfn_to_page(vcpu->kvm, pdpt_gfn);
- if (!page) {
+ ret = kvm_read_guest_page(vcpu->kvm, pdpt_gfn, pdpte,
+ offset * sizeof(u64), sizeof(pdpte));
+ if (ret < 0) {
ret = 0;
goto out;
}
-
- pdpt = kmap_atomic(page, KM_USER0);
- memcpy(pdpte, pdpt+offset, sizeof(pdpte));
- kunmap_atomic(pdpt, KM_USER0);
-
for (i = 0; i < ARRAY_SIZE(pdpte); ++i) {
if ((pdpte[i] & 1) && (pdpte[i] & 0xfffffff0000001e6ull)) {
ret = 0;
@@ -962,6 +956,127 @@ struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
}
EXPORT_SYMBOL_GPL(gfn_to_page);
+static int next_segment(unsigned long len, int offset)
+{
+ if (len > PAGE_SIZE - offset)
+ return PAGE_SIZE - offset;
+ else
+ return len;
+}
+
+int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
+ int len)
+{
+ void *page_virt;
+ struct page *page;
+
+ page = gfn_to_page(kvm, gfn);
+ if (!page)
+ return -EFAULT;
+ page_virt = kmap_atomic(page, KM_USER0);
+
+ memcpy(data, page_virt + offset, len);
+
+ kunmap_atomic(page_virt, KM_USER0);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_read_guest_page);
+
+int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
+{
+ gfn_t gfn = gpa >> PAGE_SHIFT;
+ int seg;
+ int offset = offset_in_page(gpa);
+ int ret;
+
+ while ((seg = next_segment(len, offset)) != 0) {
+ ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
+ if (ret < 0)
+ return ret;
+ offset = 0;
+ len -= seg;
+ data += seg;
+ ++gfn;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_read_guest);
+
+int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
+ int offset, int len)
+{
+ void *page_virt;
+ struct page *page;
+
+ page = gfn_to_page(kvm, gfn);
+ if (!page)
+ return -EFAULT;
+ page_virt = kmap_atomic(page, KM_USER0);
+
+ memcpy(page_virt + offset, data, len);
+
+ kunmap_atomic(page_virt, KM_USER0);
+ mark_page_dirty(kvm, gfn);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_write_guest_page);
+
+int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
+ unsigned long len)
+{
+ gfn_t gfn = gpa >> PAGE_SHIFT;
+ int seg;
+ int offset = offset_in_page(gpa);
+ int ret;
+
+ while ((seg = next_segment(len, offset)) != 0) {
+ ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
+ if (ret < 0)
+ return ret;
+ offset = 0;
+ len -= seg;
+ data += seg;
+ ++gfn;
+ }
+ return 0;
+}
+
+int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
+{
+ void *page_virt;
+ struct page *page;
+
+ page = gfn_to_page(kvm, gfn);
+ if (!page)
+ return -EFAULT;
+ page_virt = kmap_atomic(page, KM_USER0);
+
+ memset(page_virt + offset, 0, len);
+
+ kunmap_atomic(page_virt, KM_USER0);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_clear_guest_page);
+
+int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
+{
+ gfn_t gfn = gpa >> PAGE_SHIFT;
+ int seg;
+ int offset = offset_in_page(gpa);
+ int ret;
+
+ while ((seg = next_segment(len, offset)) != 0) {
+ ret = kvm_clear_guest_page(kvm, gfn, offset, seg);
+ if (ret < 0)
+ return ret;
+ offset = 0;
+ len -= seg;
+ ++gfn;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_clear_guest);
+
/* WARNING: Does not work on aliased pages. */
void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
{
@@ -988,21 +1103,13 @@ int emulator_read_std(unsigned long addr,
gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
unsigned offset = addr & (PAGE_SIZE-1);
unsigned tocopy = min(bytes, (unsigned)PAGE_SIZE - offset);
- unsigned long pfn;
- struct page *page;
- void *page_virt;
+ int ret;
if (gpa == UNMAPPED_GVA)
return X86EMUL_PROPAGATE_FAULT;
- pfn = gpa >> PAGE_SHIFT;
- page = gfn_to_page(vcpu->kvm, pfn);
- if (!page)
+ ret = kvm_read_guest(vcpu->kvm, gpa, data, tocopy);
+ if (ret < 0)
return X86EMUL_UNHANDLEABLE;
- page_virt = kmap_atomic(page, KM_USER0);
-
- memcpy(data, page_virt + offset, tocopy);
-
- kunmap_atomic(page_virt, KM_USER0);
bytes -= tocopy;
data += tocopy;
@@ -1095,19 +1202,12 @@ static int emulator_read_emulated(unsigned long addr,
static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
const void *val, int bytes)
{
- struct page *page;
- void *virt;
+ int ret;
- if (((gpa + bytes - 1) >> PAGE_SHIFT) != (gpa >> PAGE_SHIFT))
- return 0;
- page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
- if (!page)
+ ret = kvm_write_guest(vcpu->kvm, gpa, val, bytes);
+ if (ret < 0)
return 0;
- mark_page_dirty(vcpu->kvm, gpa >> PAGE_SHIFT);
- virt = kmap_atomic(page, KM_USER0);
kvm_mmu_pte_write(vcpu, gpa, val, bytes);
- memcpy(virt + offset_in_page(gpa), val, bytes);
- kunmap_atomic(virt, KM_USER0);
return 1;
}
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index c87f52b..ce15e51 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -1387,33 +1387,28 @@ static void vmx_set_gdt(struct kvm_vcpu *vcpu, struct descriptor_table *dt)
static int init_rmode_tss(struct kvm* kvm)
{
- struct page *p1, *p2, *p3;
gfn_t fn = rmode_tss_base(kvm) >> PAGE_SHIFT;
- char *page;
-
- p1 = gfn_to_page(kvm, fn++);
- p2 = gfn_to_page(kvm, fn++);
- p3 = gfn_to_page(kvm, fn);
+ u16 data = 0;
+ int r;
- if (!p1 || !p2 || !p3) {
- kvm_printf(kvm,"%s: gfn_to_page failed\n", __FUNCTION__);
+ r = kvm_clear_guest_page(kvm, fn, 0, PAGE_SIZE);
+ if (r < 0)
+ return 0;
+ data = TSS_BASE_SIZE + TSS_REDIRECTION_SIZE;
+ r = kvm_write_guest_page(kvm, fn++, &data, 0x66, sizeof(u16));
+ if (r < 0)
+ return 0;
+ r = kvm_clear_guest_page(kvm, fn++, 0, PAGE_SIZE);
+ if (r < 0)
+ return 0;
+ r = kvm_clear_guest_page(kvm, fn, 0, PAGE_SIZE);
+ if (r < 0)
+ return 0;
+ data = ~0;
+ r = kvm_write_guest_page(kvm, fn, &data, RMODE_TSS_SIZE - 2 * PAGE_SIZE - 1,
+ sizeof(u8));
+ if (r < 0)
return 0;
- }
-
- page = kmap_atomic(p1, KM_USER0);
- clear_page(page);
- *(u16*)(page + 0x66) = TSS_BASE_SIZE + TSS_REDIRECTION_SIZE;
- kunmap_atomic(page, KM_USER0);
-
- page = kmap_atomic(p2, KM_USER0);
- clear_page(page);
- kunmap_atomic(page, KM_USER0);
-
- page = kmap_atomic(p3, KM_USER0);
- clear_page(page);
- *(page + RMODE_TSS_SIZE - 2 * PAGE_SIZE - 1) = ~0;
- kunmap_atomic(page, KM_USER0);
-
return 1;
}
--
1.5.3.7
--
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