qemu/stubs/ram-block.c
David Hildenbrand b430b51395 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>
2020-11-16 13:22:17 -05:00

38 lines
554 B
C

#include "qemu/osdep.h"
#include "exec/ramlist.h"
#include "exec/cpu-common.h"
#include "exec/memory.h"
void *qemu_ram_get_host_addr(RAMBlock *rb)
{
return 0;
}
ram_addr_t qemu_ram_get_offset(RAMBlock *rb)
{
return 0;
}
ram_addr_t qemu_ram_get_used_length(RAMBlock *rb)
{
return 0;
}
void ram_block_notifier_add(RAMBlockNotifier *n)
{
}
void ram_block_notifier_remove(RAMBlockNotifier *n)
{
}
int qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque)
{
return 0;
}
int ram_block_discard_disable(bool state)
{
return 0;
}