[GIT PULL] KVM: x86: Two KVM fixes and a selftest fix

From: Sean Christopherson
Date: Thu Aug 21 2025 - 17:33:19 EST


Please pull a few small KVM x86 fixes, along with a rather ugly selftest
fix to resolve a collision with linux/overflow.h. Sadly, my attempt at a
less ugly fix fell flat, as trying to share linux/overflow.h's definition
doesn't work since not all selftests add tools/include to their include path.

Unrelated to this pull request, shameless plug for the guest_memfd mmap()
series[1]. We'd like to get it merged sooner than later as there's a bit of a
logjam of guest_memfd code piling up. And I've promised others I'll yolo it
into kvm-x86 at the end of next week if necessary :-)

Thanks!

P.S. the guest_memfd mmap() series needs one minor fixup in patch 23[2]:

diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing/selftests/kvm/guest_memfd_test.c
index b86bf89a71e0..b3ca6737f304 100644
--- a/tools/testing/selftests/kvm/guest_memfd_test.c
+++ b/tools/testing/selftests/kvm/guest_memfd_test.c
@@ -372,7 +372,7 @@ int main(int argc, char *argv[])
*/
vm_types = kvm_check_cap(KVM_CAP_VM_TYPES);
if (!vm_types)
- vm_types = VM_TYPE_DEFAULT;
+ vm_types = BIT(VM_TYPE_DEFAULT);

for_each_set_bit(vm_type, &vm_types, BITS_PER_TYPE(vm_types))
test_guest_memfd(vm_type);

[1] https://lore.kernel.org/all/20250729225455.670324-1-seanjc@xxxxxxxxxx
[2] https://lore.kernel.org/all/aIoWosN3UiPe2qQK@xxxxxxxxxx


The following changes since commit 8f5ae30d69d7543eee0d70083daf4de8fe15d585:

Linux 6.17-rc1 (2025-08-10 19:41:16 +0300)

are available in the Git repository at:

https://github.com/kvm-x86/linux.git tags/kvm-x86-fixes-6.17-rc7

for you to fetch changes up to dce1b33ed7430c7189b8cc1567498f9e6bf12731:

selftests: harness: Rename is_signed_type() to avoid collision with overflow.h (2025-08-20 08:04:09 -0700)

----------------------------------------------------------------
KVM x86 fixes and a selftest fix for 6.17-rcN

- Use array_index_nospec() to sanitize the target vCPU ID when handling PV
IPIs and yields as the ID is guest-controlled.

- Drop a superfluous cpumask_empty() check when reclaiming SEV memory, as
the common case, by far, is that at least one CPU will have entered the
VM, and wbnoinvd_on_cpus_mask() will naturally handle the rare case where
the set of have_run_cpus is empty.

- Rename the is_signed_type() macro in kselftest_harness.h to is_signed_var()
to fix a collision with linux/overflow.h. The collision generates compiler
warnings due to the two macros having different implementations.

----------------------------------------------------------------
Sean Christopherson (1):
selftests: harness: Rename is_signed_type() to avoid collision with overflow.h

Thijs Raymakers (1):
KVM: x86: use array_index_nospec with indices that come from guest

Yury Norov (1):
KVM: SEV: don't check have_run_cpus in sev_writeback_caches()

arch/x86/kvm/lapic.c | 2 ++
arch/x86/kvm/svm/sev.c | 10 +++-------
arch/x86/kvm/x86.c | 7 +++++--
tools/testing/selftests/kselftest_harness.h | 4 ++--
4 files changed, 12 insertions(+), 11 deletions(-)