mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-29 05:44:11 +00:00
Code Issues Releases Wiki Activity

KVM: arm64: selftests: Don't identity map the ucall MMIO hole

Browse source 
Currently the ucall MMIO hole is placed immediately after slot0, which
is a relatively safe address in the PA space. However, it is possible
that the same address has already been used for something else (like the
guest program image) in the VA space. At least in my own testing,
building the vgic_irq test with clang leads to the MMIO hole appearing
underneath gicv3_ops.

Stop identity mapping the MMIO hole and instead find an unused VA to map
to it. Yet another subtle detail of the KVM selftests library is that
virt_pg_map() does not update vm->vpages_mapped. Switch over to
virt_map() instead to guarantee that the chosen VA isn't to something
else.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Message-Id: <20221209015307.1781352-6-oliver.upton@linux.dev>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Oliver Upton 2022-12-09 01:53:04 +00:00 committed by Paolo Bonzini
parent feb84f6daa
commit 7a16142505
1 changed files with 4 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
tools/testing/selftests/kvm/lib/aarch64/ucall.c
View file

@ -14,11 +14,13 @@ static vm_vaddr_t *ucall_exit_mmio_addr;
void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa)
{
virt_pg_map(vm, mmio_gpa, mmio_gpa);
vm_vaddr_t mmio_gva = vm_vaddr_unused_gap(vm, vm->page_size, KVM_UTIL_MIN_VADDR);
virt_map(vm, mmio_gva, mmio_gpa, 1);
vm->ucall_mmio_addr = mmio_gpa;
write_guest_global(vm, ucall_exit_mmio_addr, (vm_vaddr_t *)mmio_gpa);
write_guest_global(vm, ucall_exit_mmio_addr, (vm_vaddr_t *)mmio_gva);
}
void ucall_arch_do_ucall(vm_vaddr_t uc)