[PATCH v2 1/7] accel/kvm: Keep track of the HWPoisonPage page_size

[“William Roche <william.roche@xxxxxxxxxx>]

From: William Roche <william.roche@xxxxxxxxxx>

When a memory page is added to the hwpoison_page_list, include
the page size information.  This size is the backend real page
size. To better deal with hugepages, we create a single entry
for the entire page.

Signed-off-by: William Roche <william.roche@xxxxxxxxxx>
---
 accel/kvm/kvm-all.c       |  8 +++++++-
 include/exec/cpu-common.h |  1 +
 system/physmem.c          | 13 +++++++++++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 801cff16a5..6dd06f5edf 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -1266,6 +1266,7 @@ int kvm_vm_check_extension(KVMState *s, unsigned int extension)
  */
 typedef struct HWPoisonPage {
     ram_addr_t ram_addr;
+    size_t     page_size;
     QLIST_ENTRY(HWPoisonPage) list;
 } HWPoisonPage;
 
@@ -1278,7 +1279,7 @@ static void kvm_unpoison_all(void *param)
 
     QLIST_FOREACH_SAFE(page, &hwpoison_page_list, list, next_page) {
         QLIST_REMOVE(page, list);
-        qemu_ram_remap(page->ram_addr, TARGET_PAGE_SIZE);
+        qemu_ram_remap(page->ram_addr, page->page_size);
         g_free(page);
     }
 }
@@ -1286,6 +1287,10 @@ static void kvm_unpoison_all(void *param)
 void kvm_hwpoison_page_add(ram_addr_t ram_addr)
 {
     HWPoisonPage *page;
+    size_t sz = qemu_ram_pagesize_from_addr(ram_addr);
+
+    if (sz > TARGET_PAGE_SIZE)
+        ram_addr = ROUND_DOWN(ram_addr, sz);
 
     QLIST_FOREACH(page, &hwpoison_page_list, list) {
         if (page->ram_addr == ram_addr) {
@@ -1294,6 +1299,7 @@ void kvm_hwpoison_page_add(ram_addr_t ram_addr)
     }
     page = g_new(HWPoisonPage, 1);
     page->ram_addr = ram_addr;
+    page->page_size = sz;
     QLIST_INSERT_HEAD(&hwpoison_page_list, page, list);
 }
 
diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index 638dc806a5..8f8f7ad567 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -108,6 +108,7 @@ bool qemu_ram_is_named_file(RAMBlock *rb);
 int qemu_ram_get_fd(RAMBlock *rb);
 
 size_t qemu_ram_pagesize(RAMBlock *block);
+size_t qemu_ram_pagesize_from_addr(ram_addr_t addr);
 size_t qemu_ram_pagesize_largest(void);
 
 /**
diff --git a/system/physmem.c b/system/physmem.c
index dc1db3a384..750604d47d 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -1665,6 +1665,19 @@ size_t qemu_ram_pagesize(RAMBlock *rb)
     return rb->page_size;
 }
 
+/* Return backend real page size used for the given ram_addr. */
+size_t qemu_ram_pagesize_from_addr(ram_addr_t addr)
+{
+    RAMBlock *rb;
+
+    RCU_READ_LOCK_GUARD();
+    rb =  qemu_get_ram_block(addr);
+    if (!rb) {
+        return TARGET_PAGE_SIZE;
+    }
+    return qemu_ram_pagesize(rb);
+}
+
 /* Returns the largest size of page in use */
 size_t qemu_ram_pagesize_largest(void)
 {
-- 
2.43.5