[PATCH v7 2/5] KVM: MMU: introduce hva_to_pfn_atomic function
Introduce hva_to_pfn_atomic(), it's the fast path and can used in atomic
context, the later patch will use it
Signed-off-by: Xiao Guangrong xiaoguangr...@cn.fujitsu.com
---
include/linux/kvm_host.h |7 +++
virt/kvm/kvm_main.c | 30 +++---
2 files changed, 26 insertions(+), 11 deletions(-)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index c13cc48..307d0e2 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -296,6 +296,7 @@ void kvm_release_page_dirty(struct page *page);
void kvm_set_page_dirty(struct page *page);
void kvm_set_page_accessed(struct page *page);
+pfn_t hva_to_pfn_atomic(struct kvm *kvm, unsigned long addr);
pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn);
pfn_t gfn_to_pfn_memslot(struct kvm *kvm,
struct kvm_memory_slot *slot, gfn_t gfn);
@@ -518,6 +519,12 @@ static inline void kvm_guest_exit(void)
current-flags = ~PF_VCPU;
}
+static inline unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot,
+ gfn_t gfn)
+{
+ return slot-userspace_addr + (gfn - slot-base_gfn) * PAGE_SIZE;
+}
+
static inline gpa_t gfn_to_gpa(gfn_t gfn)
{
return (gpa_t)gfn PAGE_SHIFT;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index b78b794..2dc0c18 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -927,11 +927,6 @@ int memslot_id(struct kvm *kvm, gfn_t gfn)
return memslot - slots-memslots;
}
-static unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot, gfn_t
gfn)
-{
- return slot-userspace_addr + (gfn - slot-base_gfn) * PAGE_SIZE;
-}
-
unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
{
struct kvm_memory_slot *slot;
@@ -943,19 +938,25 @@ unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
}
EXPORT_SYMBOL_GPL(gfn_to_hva);
-static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr)
+static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic)
{
struct page *page[1];
int npages;
pfn_t pfn;
- might_sleep();
-
- npages = get_user_pages_fast(addr, 1, 1, page);
+ if (atomic)
+ npages = __get_user_pages_fast(addr, 1, 1, page);
+ else {
+ might_sleep();
+ npages = get_user_pages_fast(addr, 1, 1, page);
+ }
if (unlikely(npages != 1)) {
struct vm_area_struct *vma;
+ if (atomic)
+ goto return_fault_page;
+
down_read(current-mm-mmap_sem);
if (is_hwpoison_address(addr)) {
up_read(current-mm-mmap_sem);
@@ -968,6 +969,7 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr)
if (vma == NULL || addr vma-vm_start ||
!(vma-vm_flags VM_PFNMAP)) {
up_read(current-mm-mmap_sem);
+return_fault_page:
get_page(fault_page);
return page_to_pfn(fault_page);
}
@@ -981,6 +983,12 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long
addr)
return pfn;
}
+pfn_t hva_to_pfn_atomic(struct kvm *kvm, unsigned long addr)
+{
+ return hva_to_pfn(kvm, addr, true);
+}
+EXPORT_SYMBOL_GPL(hva_to_pfn_atomic);
+
pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
{
unsigned long addr;
@@ -991,7 +999,7 @@ pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
return page_to_pfn(bad_page);
}
- return hva_to_pfn(kvm, addr);
+ return hva_to_pfn(kvm, addr, false);
}
EXPORT_SYMBOL_GPL(gfn_to_pfn);
@@ -999,7 +1007,7 @@ pfn_t gfn_to_pfn_memslot(struct kvm *kvm,
struct kvm_memory_slot *slot, gfn_t gfn)
{
unsigned long addr = gfn_to_hva_memslot(slot, gfn);
- return hva_to_pfn(kvm, addr);
+ return hva_to_pfn(kvm, addr, false);
}
struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
--
1.7.0.4
--
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[PATCH v7 2/5] KVM: MMU: introduce hva_to_pfn_atomic function
Introduce hva_to_pfn_atomic(), it's the fast path and can used in atomic
context, the later patch will use it
Signed-off-by: Xiao Guangrong xiaoguangr...@cn.fujitsu.com
---
include/linux/kvm_host.h |7 +++
virt/kvm/kvm_main.c | 30 +++---
2 files changed, 26 insertions(+), 11 deletions(-)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index c13cc48..307d0e2 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -296,6 +296,7 @@ void kvm_release_page_dirty(struct page *page);
void kvm_set_page_dirty(struct page *page);
void kvm_set_page_accessed(struct page *page);
+pfn_t hva_to_pfn_atomic(struct kvm *kvm, unsigned long addr);
pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn);
pfn_t gfn_to_pfn_memslot(struct kvm *kvm,
struct kvm_memory_slot *slot, gfn_t gfn);
@@ -518,6 +519,12 @@ static inline void kvm_guest_exit(void)
current-flags = ~PF_VCPU;
}
+static inline unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot,
+ gfn_t gfn)
+{
+ return slot-userspace_addr + (gfn - slot-base_gfn) * PAGE_SIZE;
+}
+
static inline gpa_t gfn_to_gpa(gfn_t gfn)
{
return (gpa_t)gfn PAGE_SHIFT;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index b78b794..2dc0c18 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -927,11 +927,6 @@ int memslot_id(struct kvm *kvm, gfn_t gfn)
return memslot - slots-memslots;
}
-static unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot, gfn_t
gfn)
-{
- return slot-userspace_addr + (gfn - slot-base_gfn) * PAGE_SIZE;
-}
-
unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
{
struct kvm_memory_slot *slot;
@@ -943,19 +938,25 @@ unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
}
EXPORT_SYMBOL_GPL(gfn_to_hva);
-static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr)
+static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic)
{
struct page *page[1];
int npages;
pfn_t pfn;
- might_sleep();
-
- npages = get_user_pages_fast(addr, 1, 1, page);
+ if (atomic)
+ npages = __get_user_pages_fast(addr, 1, 1, page);
+ else {
+ might_sleep();
+ npages = get_user_pages_fast(addr, 1, 1, page);
+ }
if (unlikely(npages != 1)) {
struct vm_area_struct *vma;
+ if (atomic)
+ goto return_fault_page;
+
down_read(current-mm-mmap_sem);
if (is_hwpoison_address(addr)) {
up_read(current-mm-mmap_sem);
@@ -968,6 +969,7 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr)
if (vma == NULL || addr vma-vm_start ||
!(vma-vm_flags VM_PFNMAP)) {
up_read(current-mm-mmap_sem);
+return_fault_page:
get_page(fault_page);
return page_to_pfn(fault_page);
}
@@ -981,6 +983,12 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long
addr)
return pfn;
}
+pfn_t hva_to_pfn_atomic(struct kvm *kvm, unsigned long addr)
+{
+ return hva_to_pfn(kvm, addr, true);
+}
+EXPORT_SYMBOL_GPL(hva_to_pfn_atomic);
+
pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
{
unsigned long addr;
@@ -991,7 +999,7 @@ pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
return page_to_pfn(bad_page);
}
- return hva_to_pfn(kvm, addr);
+ return hva_to_pfn(kvm, addr, false);
}
EXPORT_SYMBOL_GPL(gfn_to_pfn);
@@ -999,7 +1007,7 @@ pfn_t gfn_to_pfn_memslot(struct kvm *kvm,
struct kvm_memory_slot *slot, gfn_t gfn)
{
unsigned long addr = gfn_to_hva_memslot(slot, gfn);
- return hva_to_pfn(kvm, addr);
+ return hva_to_pfn(kvm, addr, false);
}
struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
--
1.7.0.4
--
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