Merge commit 'e7bdea7750eb'

Needed in order to work on top of pNFS changes in Linus' upstream kernel.

1 files changed, 13 insertions, 6 deletions

diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
index 396df6eb0a12..645c8a1982a7 100644
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -1636,6 +1636,7 @@ enum emulation_result kvm_mips_emulate_cache(uint32_t inst, uint32_t *opc,
 		if (index < 0) {
 			vcpu->arch.host_cp0_entryhi = (va & VPN2_MASK);
 			vcpu->arch.host_cp0_badvaddr = va;
+			vcpu->arch.pc = curr_pc;
 			er = kvm_mips_emulate_tlbmiss_ld(cause, NULL, run,
 							 vcpu);
 			preempt_enable();
@@ -1647,6 +1648,8 @@ enum emulation_result kvm_mips_emulate_cache(uint32_t inst, uint32_t *opc,
 			 * invalid exception to the guest
 			 */
 			if (!TLB_IS_VALID(*tlb, va)) {
+				vcpu->arch.host_cp0_badvaddr = va;
+				vcpu->arch.pc = curr_pc;
 				er = kvm_mips_emulate_tlbinv_ld(cause, NULL,
 								run, vcpu);
 				preempt_enable();
@@ -1666,7 +1669,7 @@ enum emulation_result kvm_mips_emulate_cache(uint32_t inst, uint32_t *opc,
 			cache, op, base, arch->gprs[base], offset);
 		er = EMULATE_FAIL;
 		preempt_enable();
-		goto dont_update_pc;
+		goto done;
 
 	}
 
@@ -1694,16 +1697,20 @@ skip_fault:
 		kvm_err("NO-OP CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
 			cache, op, base, arch->gprs[base], offset);
 		er = EMULATE_FAIL;
-		preempt_enable();
-		goto dont_update_pc;
 	}
 
 	preempt_enable();
+done:
+	/* Rollback PC only if emulation was unsuccessful */
+	if (er == EMULATE_FAIL)
+		vcpu->arch.pc = curr_pc;
 
 dont_update_pc:
-	/* Rollback PC */
-	vcpu->arch.pc = curr_pc;
-done:
+	/*
+	 * This is for exceptions whose emulation updates the PC, so do not
+	 * overwrite the PC under any circumstances
+	 */
+
 	return er;
 }