[PATCH v4 3/7] accel/kvm: Report the loss of a large memory page

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

From: William Roche <william.roche@xxxxxxxxxx>

In case of a large page impacted by a memory error, enhance
the existing Qemu error message which indicates that the error
is injected in the VM, adding "on lost large page SIZE@ADDR".

Include also a similar message to the ARM platform.

In the case of a large page impacted, we now report:
...Memory Error at QEMU addr X and GUEST addr Y on lost large page SIZE@ADDR of type...

Signed-off-by: William Roche <william.roche@xxxxxxxxxx>
---
 accel/kvm/kvm-all.c   |  4 ----
 target/arm/kvm.c      | 13 +++++++++++++
 target/i386/kvm/kvm.c | 18 ++++++++++++++----
 3 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 24c0c4ce3f..8a47aa7258 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -1286,10 +1286,6 @@ static void kvm_unpoison_all(void *param)
 void kvm_hwpoison_page_add(ram_addr_t ram_addr)
 {
     HWPoisonPage *page;
-    size_t page_size = qemu_ram_pagesize_from_addr(ram_addr);
-
-    if (page_size > TARGET_PAGE_SIZE)
-        ram_addr = QEMU_ALIGN_DOWN(ram_addr, page_size);
 
     QLIST_FOREACH(page, &hwpoison_page_list, list) {
         if (page->ram_addr == ram_addr) {
diff --git a/target/arm/kvm.c b/target/arm/kvm.c
index 7b6812c0de..db234f79cc 100644
--- a/target/arm/kvm.c
+++ b/target/arm/kvm.c
@@ -2366,6 +2366,8 @@ void kvm_arch_on_sigbus_vcpu(CPUState *c, int code, void *addr)
 {
     ram_addr_t ram_addr;
     hwaddr paddr;
+    size_t page_size;
+    char lp_msg[54];
 
     assert(code == BUS_MCEERR_AR || code == BUS_MCEERR_AO);
 
@@ -2373,6 +2375,14 @@ void kvm_arch_on_sigbus_vcpu(CPUState *c, int code, void *addr)
         ram_addr = qemu_ram_addr_from_host(addr);
         if (ram_addr != RAM_ADDR_INVALID &&
             kvm_physical_memory_addr_from_host(c->kvm_state, addr, &paddr)) {
+            page_size = qemu_ram_pagesize_from_addr(ram_addr);
+            if (page_size > TARGET_PAGE_SIZE) {
+                ram_addr = ROUND_DOWN(ram_addr, page_size);
+                snprintf(lp_msg, sizeof(lp_msg), " on lost large page "
+                    RAM_ADDR_FMT "@" RAM_ADDR_FMT "", page_size, ram_addr);
+            } else {
+                lp_msg[0] = '\0';
+            }
             kvm_hwpoison_page_add(ram_addr);
             /*
              * If this is a BUS_MCEERR_AR, we know we have been called
@@ -2389,6 +2399,9 @@ void kvm_arch_on_sigbus_vcpu(CPUState *c, int code, void *addr)
                 kvm_cpu_synchronize_state(c);
                 if (!acpi_ghes_record_errors(ACPI_HEST_SRC_ID_SEA, paddr)) {
                     kvm_inject_arm_sea(c);
+                    error_report("Guest Memory Error at QEMU addr %p and "
+                        "GUEST addr 0x%" HWADDR_PRIx "%s of type %s injected",
+                        addr, paddr, lp_msg, "BUS_MCEERR_AR");
                 } else {
                     error_report("failed to record the error");
                     abort();
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 8e17942c3b..336646ed61 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -741,6 +741,8 @@ void kvm_arch_on_sigbus_vcpu(CPUState *c, int code, void *addr)
     CPUX86State *env = &cpu->env;
     ram_addr_t ram_addr;
     hwaddr paddr;
+    size_t page_size;
+    char lp_msg[54];
 
     /* If we get an action required MCE, it has been injected by KVM
      * while the VM was running.  An action optional MCE instead should
@@ -753,6 +755,14 @@ void kvm_arch_on_sigbus_vcpu(CPUState *c, int code, void *addr)
         ram_addr = qemu_ram_addr_from_host(addr);
         if (ram_addr != RAM_ADDR_INVALID &&
             kvm_physical_memory_addr_from_host(c->kvm_state, addr, &paddr)) {
+            page_size = qemu_ram_pagesize_from_addr(ram_addr);
+            if (page_size > TARGET_PAGE_SIZE) {
+                ram_addr = ROUND_DOWN(ram_addr, page_size);
+                snprintf(lp_msg, sizeof(lp_msg), " on lost large page "
+                        RAM_ADDR_FMT "@" RAM_ADDR_FMT "", page_size, ram_addr);
+            } else {
+                lp_msg[0] = '\0';
+            }
             kvm_hwpoison_page_add(ram_addr);
             kvm_mce_inject(cpu, paddr, code);
 
@@ -763,12 +773,12 @@ void kvm_arch_on_sigbus_vcpu(CPUState *c, int code, void *addr)
              */
             if (code == BUS_MCEERR_AR) {
                 error_report("Guest MCE Memory Error at QEMU addr %p and "
-                    "GUEST addr 0x%" HWADDR_PRIx " of type %s injected",
-                    addr, paddr, "BUS_MCEERR_AR");
+                    "GUEST addr 0x%" HWADDR_PRIx "%s of type %s injected",
+                    addr, paddr, lp_msg, "BUS_MCEERR_AR");
             } else {
                  warn_report("Guest MCE Memory Error at QEMU addr %p and "
-                     "GUEST addr 0x%" HWADDR_PRIx " of type %s injected",
-                     addr, paddr, "BUS_MCEERR_AO");
+                     "GUEST addr 0x%" HWADDR_PRIx "%s of type %s injected",
+                     addr, paddr, lp_msg, "BUS_MCEERR_AO");
             }
 
             return;
-- 
2.43.5