diff options
| author | David Hildenbrand <david@redhat.com> | 2020-11-16 11:59:47 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-11-16 13:22:17 -0500 |
| commit | b430b51395650137a80e78ee7395165b80fe1752 (patch) | |
| tree | 4857d2981dcaf46f1685610f075eb3e06603d5d8 /util | |
| parent | 2654ace151c07bd6519a7b71ab98d763137302eb (diff) | |
util/vfio-helpers.c: Use ram_block_discard_disable() in qemu_vfio_open_pci()
Currently, when using "nvme://" for a block device, like
-drive file=nvme://0000:01:00.0/1,if=none,id=drive0 \
-device virtio-blk,drive=drive0 \
VFIO may pin all guest memory, and discarding of RAM no longer works as
expected. I was able to reproduce this easily with my
01:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd
NVMe SSD Controller SM981/PM981/PM983
Similar to common VFIO, we have to disable it, making sure that:
a) virtio-balloon won't discard any memory ("silently disabled")
b) virtio-mem and nvme:// run mutually exclusive
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20201116105947.9194-1-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'util')
| -rw-r--r-- | util/vfio-helpers.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c index c469beb061..2bec48e163 100644 --- a/util/vfio-helpers.c +++ b/util/vfio-helpers.c @@ -16,6 +16,7 @@ #include "qapi/error.h" #include "exec/ramlist.h" #include "exec/cpu-common.h" +#include "exec/memory.h" #include "trace.h" #include "qemu/error-report.h" #include "standard-headers/linux/pci_regs.h" @@ -494,8 +495,20 @@ QEMUVFIOState *qemu_vfio_open_pci(const char *device, Error **errp) int r; QEMUVFIOState *s = g_new0(QEMUVFIOState, 1); + /* + * VFIO may pin all memory inside mappings, resulting it in pinning + * all memory inside RAM blocks unconditionally. + */ + r = ram_block_discard_disable(true); + if (r) { + error_setg_errno(errp, -r, "Cannot set discarding of RAM broken"); + g_free(s); + return NULL; + } + r = qemu_vfio_init_pci(s, device, errp); if (r) { + ram_block_discard_disable(false); g_free(s); return NULL; } @@ -837,4 +850,5 @@ void qemu_vfio_close(QEMUVFIOState *s) close(s->device); close(s->group); close(s->container); + ram_block_discard_disable(false); } |