On 22.10.24 23:35, “William Roche wrote:
From: William Roche <william.roche@xxxxxxxxxx> Add the page size information to the hwpoison_page_list elements. As the kernel doesn't always report the actual poisoned page size, we adjust this size from the backend real page size. We take into account the recorded page size to adjust the size and location of the memory hole. Signed-off-by: William Roche <william.roche@xxxxxxxxxx> --- accel/kvm/kvm-all.c | 14 ++++++++++---- include/exec/cpu-common.h | 1 + include/sysemu/kvm.h | 3 ++- include/sysemu/kvm_int.h | 3 ++- system/physmem.c | 20 ++++++++++++++++++++ target/arm/kvm.c | 8 ++++++-- target/i386/kvm/kvm.c | 8 ++++++-- 7 files changed, 47 insertions(+), 10 deletions(-) diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index 2adc4d9c24..40117eefa7 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;@@ -1278,15 +1279,18 @@ 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);
Can't we just use the page size from the RAMBlock in qemu_ram_remap? There we lookup the RAMBlock, and all pages in a RAMBlock have the same size.
I'll note that qemu_ram_remap() is rather stupid and optimized only for private memory (not shmem etc).
mmap(MAP_FIXED|MAP_SHARED, fd) will give you the same poisoned page from the pagecache; you'd have to punch a hole instead.
It might be better to use ram_block_discard_range() in the long run. Memory preallocation + page pinning is tricky, but we could simply bail out in these cases (preallocation failing, ram discard being disabled).
qemu_ram_remap() might be problematic with page pinning (vfio) as is in any way :(
-- Cheers, David / dhildenb
