Commit dea4c3b2 authored by Sean Christopherson's avatar Sean Christopherson Committed by Yu Zhang
Browse files

KVM: x86/mmu: Allow yielding during MMU notifier unmap/zap, if possible 

mainline inclusion
from mainline-v5.13-rc1
commit e1eed584
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I7S3VQ
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e1eed5847b09fe41d4db4b86f9d840aba869c905



----------------------------------------------------------------------

Let the TDP MMU yield when unmapping a range in response to a MMU
notification, if yielding is allowed by said notification.  There is no
reason to disallow yielding in this case, and in theory the range being
invalidated could be quite large.

Cc: Ben Gardon <bgardon@google.com>
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20210402005658.3024832-11-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarYu Zhang <yu.c.zhang@linux.intel.com>
parent 12e0edba

arch/x86/kvm/mmu/tdp_mmu.c

+5 −1
Original line number Diff line number Diff line
@@ -880,7 +880,7 @@ bool kvm_tdp_mmu_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range, 


	for_each_tdp_mmu_root(kvm, root, range->slot->as_id)

		flush |= zap_gfn_range(kvm, root, range->start, range->end,

				       false, flush);

				       range->may_block, flush);



	return flush;

}
@@ -898,6 +898,10 @@ static __always_inline bool kvm_tdp_mmu_handle_gfn(struct kvm *kvm, 


	rcu_read_lock();



	/*

	 * Don't support rescheduling, none of the MMU notifiers that funnel

	 * into this helper allow blocking; it'd be dead, wasteful code.

	 */

	for_each_tdp_mmu_root(kvm, root, range->slot->as_id) {

		tdp_root_for_each_leaf_pte(iter, root, range->start, range->end)

			ret |= handler(kvm, &iter, range);