github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-11-07 06:17:02 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

KVM: arm64: vgic: Stop the target vcpu when disabling LPIs

Browse Source 
Disabling LPIs is pretty nasty, as it directly messes with the AP list
of the affected CPU, which could be running... This has the potential to
lead to really bad behaviours, and we should not be doing that.

Take example on the way the Active state is handled and simply pause the
the vcpu so that we are sure it is in a quiescent state, and the state be
safely manipulated.

Nobody has any expectation of performance for this anyway.

Fixes: 96085b9496 ("KVM: arm/arm64: vgic-v3: Retire pending interrupts on disabling LPIs")
Co-developed-by: Oliver Upton <oupton@kernel.org>
Signed-off-by: Oliver Upton <oupton@kernel.org>
Cc: stable@vger.kernel.org
Reviewed-by: Fuad Tabba <fuad.tabba@linux.dev>
Tested-by: Fuad Tabba <fuad.tabba@linux.dev>
Link: https://patch.msgid.link/20261015100539.1011760-7-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
This commit is contained in:
Marc Zyngier 2026-10-15 11:05:38 +01:00
parent 134b6486dd
commit a1b4bd2c2c
1 changed files with 10 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
arch/arm64/kvm/vgic/vgic-mmio-v3.c
View File

@ -303,9 +303,19 @@ static void vgic_mmio_write_v3r_ctlr(struct kvm_vcpu *vcpu,
if (ctlr != GICR_CTLR_ENABLE_LPIS)
return;
/*
* Yes, disabling LPIs is painful, since it can be done from
* a *remote* vcpu! So let's not take any chance, and make
* sure that the target vCPU has written their LRs back to the
* irq structures, and release any reference they would have.
*
* If it hurts, don't do it.
*/
kvm_pause_vcpu(vcpu);
vgic_flush_pending_lpis(vcpu);
vgic_its_invalidate_all_caches(vcpu->kvm);
atomic_set_release(&vgic_cpu->ctlr, 0);
kvm_resume_vcpu(vcpu);
} else {
ctlr = atomic_cmpxchg_acquire(&vgic_cpu->ctlr, 0,
GICR_CTLR_ENABLE_LPIS);