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migration: prevent migration when VM has poisoned memory

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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>
Link: https://lore.kernel.org/r/20240130190640.139364-2-william.roche@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>
This commit is contained in:
William Roche 2024-01-30 19:06:40 +00:00 • committed by Peter Xu
parent 39a6e4f87e
commit 06152b89db
4 changed files with 28 additions and 0 deletions
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10
accel/kvm/kvm-all.c
View file

@ -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