> From: Jason Gunthorpe <jgg@xxxxxxxxxx> > Sent: Wednesday, June 14, 2023 7:53 PM > > On Wed, Jun 14, 2023 at 08:07:30AM +0000, Tian, Kevin wrote: > > > think of a scenario where the vbios memory is shared by multiple qemu > > instances then RW allows a malicious VM to modify the shared content > > then potentially attacking other VMs. > > qemu would have to map the vbios as MAP_PRIVATE WRITE before the > iommu > side could map it writable, so this is not a real worry. > Make sense. but IMHO it's still safer to reduce the permission (RO->NP) than increasing the permission (RO->RW) when faithfully emulating bare metal behavior is impossible, especially when there is no real usage counting on it. 😊
