| Message ID | 20240130190640.139364-2-william.roche@oracle.com |
|---|---|
| State | New |
| Headers | show |
| Series | Qemu crashes on VM migration after an handled memory error | expand |
On Tue, Jan 30, 2024 at 07:06:40PM +0000, “William Roche wrote: > From: William Roche <william.roche@oracle.com> > > A memory page poisoned from the hypervisor level is no longer readable. > The migration of a VM will crash Qemu when it tries to read the > memory address space and stumbles on the poisoned page with a similar > stack trace: > > Program terminated with signal SIGBUS, Bus error. > #0 _mm256_loadu_si256 > #1 buffer_zero_avx2 > #2 select_accel_fn > #3 buffer_is_zero > #4 save_zero_page > #5 ram_save_target_page_legacy > #6 ram_save_host_page > #7 ram_find_and_save_block > #8 ram_save_iterate > #9 qemu_savevm_state_iterate > #10 migration_iteration_run > #11 migration_thread > #12 qemu_thread_start > > To avoid this VM crash during the migration, prevent the migration > when a known hardware poison exists on the VM. > > Signed-off-by: William Roche <william.roche@oracle.com> I queued it for now, while it'll always good to get feedback from either Paolo or anyone else, as the pull won't happen in one week. If no objection it'll be included the next migration pull. Thanks,
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index 49e755ec4a..a8cecd040e 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -1119,6 +1119,11 @@ int kvm_vm_check_extension(KVMState *s, unsigned int extension) return ret; } +/* + * We track the poisoned pages to be able to: + * - replace them on VM reset + * - block a migration for a VM with a poisoned page + */ typedef struct HWPoisonPage { ram_addr_t ram_addr; QLIST_ENTRY(HWPoisonPage) list; @@ -1152,6 +1157,11 @@ void kvm_hwpoison_page_add(ram_addr_t ram_addr) QLIST_INSERT_HEAD(&hwpoison_page_list, page, list); } +bool kvm_hwpoisoned_mem(void) +{ + return !QLIST_EMPTY(&hwpoison_page_list); +} + static uint32_t adjust_ioeventfd_endianness(uint32_t val, uint32_t size) { #if HOST_BIG_ENDIAN != TARGET_BIG_ENDIAN diff --git a/accel/stubs/kvm-stub.c b/accel/stubs/kvm-stub.c index 1b37d9a302..ca38172884 100644 --- a/accel/stubs/kvm-stub.c +++ b/accel/stubs/kvm-stub.c @@ -124,3 +124,8 @@ uint32_t kvm_dirty_ring_size(void) { return 0; } + +bool kvm_hwpoisoned_mem(void) +{ + return false; +} diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h index d614878164..fad9a7e8ff 100644 --- a/include/sysemu/kvm.h +++ b/include/sysemu/kvm.h @@ -538,4 +538,10 @@ bool kvm_arch_cpu_check_are_resettable(void); bool kvm_dirty_ring_enabled(void); uint32_t kvm_dirty_ring_size(void); + +/** + * kvm_hwpoisoned_mem - indicate if there is any hwpoisoned page + * reported for the VM. + */ +bool kvm_hwpoisoned_mem(void); #endif diff --git a/migration/migration.c b/migration/migration.c index d5f705ceef..b574e66f7b 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -67,6 +67,7 @@ #include "options.h" #include "sysemu/dirtylimit.h" #include "qemu/sockets.h" +#include "sysemu/kvm.h" static NotifierList migration_state_notifiers = NOTIFIER_LIST_INITIALIZER(migration_state_notifiers); @@ -1906,6 +1907,12 @@ static bool migrate_prepare(MigrationState *s, bool blk, bool blk_inc, return false; } + if (kvm_hwpoisoned_mem()) { + error_setg(errp, "Can't migrate this vm with hardware poisoned memory, " + "please reboot the vm and try again"); + return false; + } + if (migration_is_blocked(errp)) { return false; }