KVM: arm64: gic-v5: Add emulation for ICC_IAFFIDR_EL1 accesses

Browse source

GICv5 doesn't provide an ICV_IAFFIDR_EL1 or ICH_IAFFIDR_EL2 for
providing the IAFFID to the guest. A guest access to the
ICC_IAFFIDR_EL1 must therefore be trapped and emulated to avoid the
guest accessing the host's ICC_IAFFIDR_EL1.

The virtual IAFFID is provided to the guest when it reads
ICC_IAFFIDR_EL1 (which always traps back to the hypervisor). Writes are
rightly ignored. KVM treats the GICv5 VPEID, the virtual IAFFID, and
the vcpu_id as the same, and so the vcpu_id is returned.

The trapping for the ICC_IAFFIDR_EL1 is always enabled when in a guest
context.

Co-authored-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20260319154937.3619520-15-sascha.bischoff@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>

...

This commit is contained in:

Sascha Bischoff 2026-03-19 15:53:21 +00:00 • committed by Marc Zyngier

parent 9d6d9514c0

commit 607871ce63

3 changed files with 30 additions and 1 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

10

arch/arm64/kvm/config.c

View file

16

arch/arm64/kvm/sys_regs.c

View file

5

arch/arm64/kvm/vgic/vgic.h

View file