Currently unmap_all is split into two ioctl() with each unmap half of
the whole iova space.
IOMMUFD supports unmap_all ioctl() from beginning, after kernel commit
c19650995374 ("vfio/type1: implement unmap all") added same support
for VFIO type1, the split becomes unnecessary.
So optimize the code to only do one ioctl() to unmap_all for both
backends.
Test:
In order to trigger unmap_all request, made below trick, during emergency
reset in guest, memory region [0xfef00000 - 0xffffffffffffffff] is
deleted, I fake it to be a unmap_all request.
--- a/hw/vfio/listener.c
+++ b/hw/vfio/listener.c
@@ -714,8 +714,10 @@ static void vfio_listener_region_del(MemoryListener
*listener,
if (try_unmap) {
bool unmap_all = false;
- if (int128_eq(llsize, int128_2_64())) {
+ if (int128_eq(llsize, int128_2_64()) ||
+ iova == 0xfef00000) {
unmap_all = true;
+ iova = 0;
llsize = int128_zero();
}
The log shows ioctl() succeed on the whole iova space:
vfio_listener_region_del region_del 0xfef00000 - 0xffffffffffffffff
iommufd_backend_unmap_dma iommufd=10 ioas=5 iova=0x0 size=0xffffffffffffffff
(0)
Same result for legacy VFIO.
Maybe it's easy to trigger unmap_all with other arch, e.g., arm smmu, but for
x86,
iommu memory region is split by iommu_ir, unmap_all isn't triggered.
Thanks
Zhenzhong
Zhenzhong Duan (2):
vfio/container: Support unmap all in one ioctl()
vfio/iommufd: Support unmap all in one ioctl()
hw/vfio/container.c | 33 ++++++++++++++++++++-------------
hw/vfio/iommufd.c | 16 ++--------------
2 files changed, 22 insertions(+), 27 deletions(-)
--
2.47.1
