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-rw-r--r--arch/x86/kvm/mmu.c34
-rw-r--r--arch/x86/kvm/paging_tmpl.h7
-rw-r--r--include/linux/kvm_host.h1
-rw-r--r--include/linux/mm.h8
-rw-r--r--mm/memory-failure.c30
-rw-r--r--virt/kvm/kvm_main.c30
6 files changed, 95 insertions, 15 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index b1ed0a1..b666d8d 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -32,6 +32,7 @@
#include <linux/compiler.h>
#include <linux/srcu.h>
#include <linux/slab.h>
+#include <linux/uaccess.h>
#include <asm/page.h>
#include <asm/cmpxchg.h>
@@ -1960,6 +1961,27 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
return pt_write;
}
+static void kvm_send_hwpoison_signal(struct kvm *kvm, gfn_t gfn)
+{
+ char buf[1];
+ void __user *hva;
+ int r;
+
+ /* Touch the page, so send SIGBUS */
+ hva = (void __user *)gfn_to_hva(kvm, gfn);
+ r = copy_from_user(buf, hva, 1);
+}
+
+static int kvm_handle_bad_page(struct kvm *kvm, gfn_t gfn, pfn_t pfn)
+{
+ kvm_release_pfn_clean(pfn);
+ if (is_hwpoison_pfn(pfn)) {
+ kvm_send_hwpoison_signal(kvm, gfn);
+ return 0;
+ }
+ return 1;
+}
+
static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
{
int r;
@@ -1983,10 +2005,8 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
pfn = gfn_to_pfn(vcpu->kvm, gfn);
/* mmio */
- if (is_error_pfn(pfn)) {
- kvm_release_pfn_clean(pfn);
- return 1;
- }
+ if (is_error_pfn(pfn))
+ return kvm_handle_bad_page(vcpu->kvm, gfn, pfn);
spin_lock(&vcpu->kvm->mmu_lock);
if (mmu_notifier_retry(vcpu, mmu_seq))
@@ -2198,10 +2218,8 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
mmu_seq = vcpu->kvm->mmu_notifier_seq;
smp_rmb();
pfn = gfn_to_pfn(vcpu->kvm, gfn);
- if (is_error_pfn(pfn)) {
- kvm_release_pfn_clean(pfn);
- return 1;
- }
+ if (is_error_pfn(pfn))
+ return kvm_handle_bad_page(vcpu->kvm, gfn, pfn);
spin_lock(&vcpu->kvm->mmu_lock);
if (mmu_notifier_retry(vcpu, mmu_seq))
goto out_unlock;
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 2331bdc..c7f2777 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -431,11 +431,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
pfn = gfn_to_pfn(vcpu->kvm, walker.gfn);
/* mmio */
- if (is_error_pfn(pfn)) {
- pgprintk("gfn %lx is mmio\n", walker.gfn);
- kvm_release_pfn_clean(pfn);
- return 1;
- }
+ if (is_error_pfn(pfn))
+ return kvm_handle_bad_page(vcpu->kvm, walker.gfn, pfn);
spin_lock(&vcpu->kvm->mmu_lock);
if (mmu_notifier_retry(vcpu, mmu_seq))
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 7cb116a..a0e0197 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -266,6 +266,7 @@ extern pfn_t bad_pfn;
int is_error_page(struct page *page);
int is_error_pfn(pfn_t pfn);
+int is_hwpoison_pfn(pfn_t pfn);
int kvm_is_error_hva(unsigned long addr);
int kvm_set_memory_region(struct kvm *kvm,
struct kvm_userspace_memory_region *mem,
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a2b4804..7a9ab7d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1465,6 +1465,14 @@ extern int sysctl_memory_failure_recovery;
extern void shake_page(struct page *p, int access);
extern atomic_long_t mce_bad_pages;
extern int soft_offline_page(struct page *page, int flags);
+#ifdef CONFIG_MEMORY_FAILURE
+int is_hwpoison_address(unsigned long addr);
+#else
+static inline int is_hwpoison_address(unsigned long addr)
+{
+ return 0;
+}
+#endif
extern void dump_page(struct page *page);
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 620b0b4..378b0f6 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -45,6 +45,7 @@
#include <linux/page-isolation.h>
#include <linux/suspend.h>
#include <linux/slab.h>
+#include <linux/swapops.h>
#include "internal.h"
int sysctl_memory_failure_early_kill __read_mostly = 0;
@@ -1296,3 +1297,32 @@ done:
/* keep elevated page count for bad page */
return ret;
}
+
+int is_hwpoison_address(unsigned long addr)
+{
+ pgd_t *pgdp;
+ pud_t pud, *pudp;
+ pmd_t pmd, *pmdp;
+ pte_t pte, *ptep;
+ swp_entry_t entry;
+
+ pgdp = pgd_offset(current->mm, addr);
+ if (!pgd_present(*pgdp))
+ return 0;
+ pudp = pud_offset(pgdp, addr);
+ pud = *pudp;
+ if (!pud_present(pud) || pud_large(pud))
+ return 0;
+ pmdp = pmd_offset(pudp, addr);
+ pmd = *pmdp;
+ if (!pmd_present(pmd) || pmd_large(pmd))
+ return 0;
+ ptep = pte_offset_map(pmdp, addr);
+ pte = *ptep;
+ pte_unmap(ptep);
+ if (!is_swap_pte(pte))
+ return 0;
+ entry = pte_to_swp_entry(pte);
+ return is_hwpoison_entry(entry);
+}
+EXPORT_SYMBOL_GPL(is_hwpoison_address);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index f032806..187aa8d 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -92,6 +92,9 @@ static bool kvm_rebooting;
static bool largepages_enabled = true;
+struct page *hwpoison_page;
+pfn_t hwpoison_pfn;
+
inline int kvm_is_mmio_pfn(pfn_t pfn)
{
if (pfn_valid(pfn)) {
@@ -810,16 +813,22 @@ EXPORT_SYMBOL_GPL(kvm_disable_largepages);
int is_error_page(struct page *page)
{
- return page == bad_page;
+ return page == bad_page || page == hwpoison_page;
}
EXPORT_SYMBOL_GPL(is_error_page);
int is_error_pfn(pfn_t pfn)
{
- return pfn == bad_pfn;
+ return pfn == bad_pfn || pfn == hwpoison_pfn;
}
EXPORT_SYMBOL_GPL(is_error_pfn);
+int is_hwpoison_pfn(pfn_t pfn)
+{
+ return pfn == hwpoison_pfn;
+}
+EXPORT_SYMBOL_GPL(is_hwpoison_pfn);
+
static inline unsigned long bad_hva(void)
{
return PAGE_OFFSET;
@@ -945,6 +954,11 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr)
if (unlikely(npages != 1)) {
struct vm_area_struct *vma;
+ if (is_hwpoison_address(addr)) {
+ get_page(hwpoison_page);
+ return page_to_pfn(hwpoison_page);
+ }
+
down_read(&current->mm->mmap_sem);
vma = find_vma(current->mm, addr);
@@ -2197,6 +2211,15 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
bad_pfn = page_to_pfn(bad_page);
+ hwpoison_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+
+ if (hwpoison_page == NULL) {
+ r = -ENOMEM;
+ goto out_free_0;
+ }
+
+ hwpoison_pfn = page_to_pfn(hwpoison_page);
+
if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) {
r = -ENOMEM;
goto out_free_0;
@@ -2269,6 +2292,8 @@ out_free_1:
out_free_0a:
free_cpumask_var(cpus_hardware_enabled);
out_free_0:
+ if (hwpoison_page)
+ __free_page(hwpoison_page);
__free_page(bad_page);
out:
kvm_arch_exit();
@@ -2290,6 +2315,7 @@ void kvm_exit(void)
kvm_arch_hardware_unsetup();
kvm_arch_exit();
free_cpumask_var(cpus_hardware_enabled);
+ __free_page(hwpoison_page);
__free_page(bad_page);
}
EXPORT_SYMBOL_GPL(kvm_exit);
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