Patch "[PATCH BACKPORT 3.10-3.15 4/4] MIPS: KVM: Propagate kseg0/mapped tlb fault errors" has been added to the 3.14-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    [PATCH BACKPORT 3.10-3.15 4/4] MIPS: KVM: Propagate kseg0/mapped tlb fault errors

to the 3.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mips-kvm-propagate-kseg0-mapped-tlb-fault-errors.patch
and it can be found in the queue-3.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From james.hogan@imgtec.com  Thu Aug 18 11:46:32 2016
From: James Hogan <james.hogan@imgtec.com>
Date: Thu, 18 Aug 2016 10:22:55 +0100
Subject: [PATCH BACKPORT 3.10-3.15 4/4] MIPS: KVM: Propagate kseg0/mapped tlb fault errors
To: <stable@vger.kernel.org>
Cc: James Hogan <james.hogan@imgtec.com>, Paolo Bonzini <pbonzini@redhat.com>, Radim Krčmář <rkrcmar@redhat.com>, Ralf Baechle <ralf@linux-mips.org>, <linux-mips@linux-mips.org>, <kvm@vger.kernel.org>
Message-ID: <f985ed835cfcabe5c7f313abd1de1bb3ee8737f9.1471021142.git-series.james.hogan@imgtec.com>

From: James Hogan <james.hogan@imgtec.com>

commit 9b731bcfdec4c159ad2e4312e25d69221709b96a upstream.

Propagate errors from kvm_mips_handle_kseg0_tlb_fault() and
kvm_mips_handle_mapped_seg_tlb_fault(), usually triggering an internal
error since they normally indicate the guest accessed bad physical
memory or the commpage in an unexpected way.

Fixes: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.")
Fixes: e685c689f3a8 ("KVM/MIPS32: Privileged instruction/target branch emulation.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
[james.hogan@imgtec.com: Backport to v3.10.y - v3.15.y]
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/mips/kvm/kvm_mips_emul.c |   33 ++++++++++++++++++++++++---------
 arch/mips/kvm/kvm_tlb.c       |   14 ++++++++++----
 2 files changed, 34 insertions(+), 13 deletions(-)

--- a/arch/mips/kvm/kvm_mips_emul.c
+++ b/arch/mips/kvm/kvm_mips_emul.c
@@ -972,8 +972,13 @@ kvm_mips_emulate_cache(uint32_t inst, ui
 	preempt_disable();
 	if (KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG0) {
 
-		if (kvm_mips_host_tlb_lookup(vcpu, va) < 0) {
-			kvm_mips_handle_kseg0_tlb_fault(va, vcpu);
+		if (kvm_mips_host_tlb_lookup(vcpu, va) < 0 &&
+		    kvm_mips_handle_kseg0_tlb_fault(va, vcpu)) {
+			kvm_err("%s: handling mapped kseg0 tlb fault for %lx, vcpu: %p, ASID: %#lx\n",
+				__func__, va, vcpu, read_c0_entryhi());
+			er = EMULATE_FAIL;
+			preempt_enable();
+			goto done;
 		}
 	} else if ((KVM_GUEST_KSEGX(va) < KVM_GUEST_KSEG0) ||
 		   KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG23) {
@@ -1006,11 +1011,16 @@ kvm_mips_emulate_cache(uint32_t inst, ui
 								run, vcpu);
 				preempt_enable();
 				goto dont_update_pc;
-			} else {
-				/* We fault an entry from the guest tlb to the shadow host TLB */
-				kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb,
-								     NULL,
-								     NULL);
+			}
+			/* We fault an entry from the guest tlb to the shadow host TLB */
+			if (kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb,
+								 NULL, NULL)) {
+				kvm_err("%s: handling mapped seg tlb fault for %lx, index: %u, vcpu: %p, ASID: %#lx\n",
+					__func__, va, index, vcpu,
+					read_c0_entryhi());
+				er = EMULATE_FAIL;
+				preempt_enable();
+				goto done;
 			}
 		}
 	} else {
@@ -1821,8 +1831,13 @@ kvm_mips_handle_tlbmiss(unsigned long ca
 			     tlb->tlb_hi, tlb->tlb_lo0, tlb->tlb_lo1);
 #endif
 			/* OK we have a Guest TLB entry, now inject it into the shadow host TLB */
-			kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb, NULL,
-							     NULL);
+			if (kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb,
+								 NULL, NULL)) {
+				kvm_err("%s: handling mapped seg tlb fault for %lx, index: %u, vcpu: %p, ASID: %#lx\n",
+					__func__, va, index, vcpu,
+					read_c0_entryhi());
+				er = EMULATE_FAIL;
+			}
 		}
 	}
 
--- a/arch/mips/kvm/kvm_tlb.c
+++ b/arch/mips/kvm/kvm_tlb.c
@@ -797,10 +797,16 @@ uint32_t kvm_get_inst(uint32_t *opc, str
 				local_irq_restore(flags);
 				return KVM_INVALID_INST;
 			}
-			kvm_mips_handle_mapped_seg_tlb_fault(vcpu,
-							     &vcpu->arch.
-							     guest_tlb[index],
-							     NULL, NULL);
+			if (kvm_mips_handle_mapped_seg_tlb_fault(vcpu,
+						&vcpu->arch.guest_tlb[index],
+						NULL, NULL)) {
+				kvm_err("%s: handling mapped seg tlb fault failed for %p, index: %u, vcpu: %p, ASID: %#lx\n",
+					__func__, opc, index, vcpu,
+					read_c0_entryhi());
+				kvm_mips_dump_guest_tlbs(vcpu);
+				local_irq_restore(flags);
+				return KVM_INVALID_INST;
+			}
 			inst = *(opc);
 		}
 		local_irq_restore(flags);


Patches currently in stable-queue which might be from james.hogan@imgtec.com are

queue-3.14/mips-kvm-add-missing-gfn-range-check.patch
queue-3.14/mips-kvm-propagate-kseg0-mapped-tlb-fault-errors.patch
queue-3.14/mips-kvm-fix-mapped-fault-broken-commpage-handling.patch
queue-3.14/mips-kvm-fix-gfn-range-check-in-kseg0-tlb-faults.patch