From: Paolo Bonzini <pbonzini@redhat.com>
Date: Tue, 30 Sep 2025 17:23:28 +0000 (-0400)
Subject: Merge tag 'kvmarm-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmar... 
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=924ebaefcec28289c210cad92551ae900e8fc220;p=users%2Fhch%2Fmisc.git

Merge tag 'kvmarm-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for 6.18

- Add support for FF-A 1.2 as the secure memory conduit for pKVM,
  allowing more registers to be used as part of the message payload.

- Change the way pKVM allocates its VM handles, making sure that the
  privileged hypervisor is never tricked into using uninitialised
  data.

- Speed up MMIO range registration by avoiding unnecessary RCU
  synchronisation, which results in VMs starting much quicker.

- Add the dump of the instruction stream when panic-ing in the EL2
  payload, just like the rest of the kernel has always done. This will
  hopefully help debugging non-VHE setups.

- Add 52bit PA support to the stage-1 page-table walker, and make use
  of it to populate the fault level reported to the guest on failing
  to translate a stage-1 walk.

- Add NV support to the GICv3-on-GICv5 emulation code, ensuring
  feature parity for guests, irrespective of the host platform.

- Fix some really ugly architecture problems when dealing with debug
  in a nested VM. This has some bad performance impacts, but is at
  least correct.

- Add enough infrastructure to be able to disable EL2 features and
  give effective values to the EL2 control registers. This then allows
  a bunch of features to be turned off, which helps cross-host
  migration.

- Large rework of the selftest infrastructure to allow most tests to
  transparently run at EL2. This is the first step towards enabling
  NV testing.

- Various fixes and improvements all over the map, including one BE
  fix, just in time for the removal of the feature.
---

924ebaefcec28289c210cad92551ae900e8fc220
diff --cc arch/arm64/kvm/mmu.c
index 217767c89b90,e574769b3330..7cc964af8d30
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@@ -1798,10 -1726,31 +1795,15 @@@ static int user_mem_abort(struct kvm_vc
  	}
  
  	if (exec_fault && s2_force_noncacheable)
- 		return -ENOEXEC;
+ 		ret = -ENOEXEC;
+ 
+ 	if (ret) {
+ 		kvm_release_page_unused(page);
+ 		return ret;
+ 	}
  
 -	/*
 -	 * Potentially reduce shadow S2 permissions to match the guest's own
 -	 * S2. For exec faults, we'd only reach this point if the guest
 -	 * actually allowed it (see kvm_s2_handle_perm_fault).
 -	 *
 -	 * Also encode the level of the original translation in the SW bits
 -	 * of the leaf entry as a proxy for the span of that translation.
 -	 * This will be retrieved on TLB invalidation from the guest and
 -	 * used to limit the invalidation scope if a TTL hint or a range
 -	 * isn't provided.
 -	 */
 -	if (nested) {
 -		writable &= kvm_s2_trans_writable(nested);
 -		if (!kvm_s2_trans_readable(nested))
 -			prot &= ~KVM_PGTABLE_PROT_R;
 -
 -		prot |= kvm_encode_nested_level(nested);
 -	}
 +	if (nested)
 +		adjust_nested_fault_perms(nested, &prot, &writable);
  
  	kvm_fault_lock(kvm);
  	pgt = vcpu->arch.hw_mmu->pgt;