On 10/04/19 02:08, Gary R Hook wrote: > Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1667249 > > On an AMD SEV enabled host with an SEV enabled guest, attaching an > assigned device to the VM results in a failure to start the VM: > > qemu-kvm: -device vfio-pci,host=01:00.0,id=hostdev0,bus=pci.2,addr=0x0: > sev_ram_block_added: failed to register region (0x7fd96e6bb000+0x20000) error > 'Cannot allocate memory' > > In this example the assigned device is a simple Intel 82574L NIC: > > 01:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network > Connection > Subsystem: Intel Corporation Gigabit CT Desktop Adapter > Flags: bus master, fast devsel, latency 0, IRQ 89, NUMA node 0 > Memory at fb9c0000 (32-bit, non-prefetchable) [size=128K] > Memory at fb900000 (32-bit, non-prefetchable) [size=512K] > > Note that the error indicates the region as (base+size) where a size > of 0x20000 is 128K, which matches that of BAR0 for the device. > dmesg on the host also reports: > > SVM: SEV: Failure locking 32 pages. > > SEV guests make use of the RAMBlock notifier in QEMU to add page > pinnings for SEV; the kernel side of the call only knows how to pin > pages with get_user_pages(), and this currently faults on non-page > backed mappings (e.g. the mmap of an MMIO BAR). > > To resolve this failure, change the order of the memory region type > assignment and avoid pinning device memory regions. > > Cc: "Danilo C. L. de Paula" <ddepa...@redhat.com> > Cc: Eduardo Habkost <ehabk...@redhat.com> > Cc: Paolo Bonzini <pbonz...@redhat.com> > Cc: qemu-devel@nongnu.org > Cc: Richard Henderson <r...@twiddle.net> > > Danilo C. L. de Paula (2): > redhat: branching qemu-kvm to rhel-8.1.0 > redhat: renaming branch to rhel-8.1.0 > > Gary R Hook (2): > Subject: memory: Fix the memory region type assignment order > Subject: target/i386: sev: Do not pin the ram device memory region > > .gitpublish | 6 +++--- > memory.c | 9 ++++++++- > target/i386/sev.c | 11 +++++++++++ > 3 files changed, 22 insertions(+), 4 deletions(-) >
Acked-by: Paolo Bonzini <pbonz...@redhat.com>
