Commit 76657687 authored by Peter Xu's avatar Peter Xu Committed by Paolo Bonzini
Browse files

kvm: x86: Allow to respond to generic signals during slow PF 



Enable x86 slow page faults to be able to respond to non-fatal signals,
returning -EINTR properly when it happens.

Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Reviewed-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20221011195947.557281-1-peterx@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent c8b88b33

arch/x86/kvm/mmu/mmu.c

+13 −3
Original line number Diff line number Diff line
@@ -3149,8 +3149,13 @@ static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct * 
	send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, PAGE_SHIFT, tsk);

}



static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn)

static int kvm_handle_error_pfn(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn)

{

	if (is_sigpending_pfn(pfn)) {

		kvm_handle_signal_exit(vcpu);

		return -EINTR;

	}



	/*

	 * Do not cache the mmio info caused by writing the readonly gfn

	 * into the spte otherwise read access on readonly gfn also can
@@ -3172,7 +3177,7 @@ static int handle_abnormal_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fau 
{

	/* The pfn is invalid, report the error! */

	if (unlikely(is_error_pfn(fault->pfn)))

		return kvm_handle_bad_page(vcpu, fault->gfn, fault->pfn);

		return kvm_handle_error_pfn(vcpu, fault->gfn, fault->pfn);



	if (unlikely(!fault->slot)) {

		gva_t gva = fault->is_tdp ? 0 : fault->addr;
@@ -4187,7 +4192,12 @@ static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) 
		}

	}



	fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, false, NULL,

	/*

	 * Allow gup to bail on pending non-fatal signals when it's also allowed

	 * to wait for IO.  Note, gup always bails if it is unable to quickly

	 * get a page and a fatal signal, i.e. SIGKILL, is pending.

	 */

	fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, true, NULL,

					  fault->write, &fault->map_writable,

					  &fault->hva);

	return RET_PF_CONTINUE;