Merge tag 'kvm-3.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "PPC and ARM do not have much going on this time.  Most of the cool
  stuff, instead, is in s390 and (after a few releases) x86.

  ARM has some caching fixes and PPC has transactional memory support in
  guests.  MIPS has some fixes, with more probably coming in 3.16 as
  QEMU will soon get support for MIPS KVM.

  For x86 there are optimizations for debug registers, which trigger on
  some Windows games, and other important fixes for Windows guests.  We
  now expose to the guest Broadwell instruction set extensions and also
  Intel MPX.  There's also a fix/workaround for OS X guests, nested
  virtualization features (preemption timer), and a couple kvmclock
  refinements.

  For s390, the main news is asynchronous page faults, together with
  improvements to IRQs (floating irqs and adapter irqs) that speed up
  virtio devices"

* tag 'kvm-3.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (96 commits)
  KVM: PPC: Book3S HV: Save/restore host PMU registers that are new in POWER8
  KVM: PPC: Book3S HV: Fix decrementer timeouts with non-zero TB offset
  KVM: PPC: Book3S HV: Don't use kvm_memslots() in real mode
  KVM: PPC: Book3S HV: Return ENODEV error rather than EIO
  KVM: PPC: Book3S: Trim top 4 bits of physical address in RTAS code
  KVM: PPC: Book3S HV: Add get/set_one_reg for new TM state
  KVM: PPC: Book3S HV: Add transactional memory support
  KVM: Specify byte order for KVM_EXIT_MMIO
  KVM: vmx: fix MPX detection
  KVM: PPC: Book3S HV: Fix KVM hang with CONFIG_KVM_XICS=n
  KVM: PPC: Book3S: Introduce hypervisor call H_GET_TCE
  KVM: PPC: Book3S HV: Fix incorrect userspace exit on ioeventfd write
  KVM: s390: clear local interrupts at cpu initial reset
  KVM: s390: Fix possible memory leak in SIGP functions
  KVM: s390: fix calculation of idle_mask array size
  KVM: s390: randomize sca address
  KVM: ioapic: reinject pending interrupts on KVM_SET_IRQCHIP
  KVM: Bump KVM_MAX_IRQ_ROUTES for s390
  KVM: s390: irq routing for adapter interrupts.
  KVM: s390: adapter interrupt sources
  ...

1 files changed, 18 insertions, 22 deletions

diff --git a/arch/mips/kvm/kvm_mips_emul.c b/arch/mips/kvm/kvm_mips_emul.c
index 4b6274b47f33..e3fec99941a7 100644
--- a/arch/mips/kvm/kvm_mips_emul.c
+++ b/arch/mips/kvm/kvm_mips_emul.c
@@ -436,13 +436,6 @@ kvm_mips_emulate_CP0(uint32_t inst, uint32_t *opc, uint32_t cause,
 	sel = inst & 0x7;
 	co_bit = (inst >> 25) & 1;
 
-	/* Verify that the register is valid */
-	if (rd > MIPS_CP0_DESAVE) {
-		printk("Invalid rd: %d\n", rd);
-		er = EMULATE_FAIL;
-		goto done;
-	}
-
 	if (co_bit) {
 		op = (inst) & 0xff;
 
@@ -1542,8 +1535,15 @@ kvm_mips_handle_ri(unsigned long cause, uint32_t *opc,
 	}
 
 	if ((inst & OPCODE) == SPEC3 && (inst & FUNC) == RDHWR) {
+		int usermode = !KVM_GUEST_KERNEL_MODE(vcpu);
 		int rd = (inst & RD) >> 11;
 		int rt = (inst & RT) >> 16;
+		/* If usermode, check RDHWR rd is allowed by guest HWREna */
+		if (usermode && !(kvm_read_c0_guest_hwrena(cop0) & BIT(rd))) {
+			kvm_debug("RDHWR %#x disallowed by HWREna @ %p\n",
+				  rd, opc);
+			goto emulate_ri;
+		}
 		switch (rd) {
 		case 0:	/* CPU number */
 			arch->gprs[rt] = 0;
@@ -1567,31 +1567,27 @@ kvm_mips_handle_ri(unsigned long cause, uint32_t *opc,
 			}
 			break;
 		case 29:
-#if 1
 			arch->gprs[rt] = kvm_read_c0_guest_userlocal(cop0);
-#else
-			/* UserLocal not implemented */
-			er = kvm_mips_emulate_ri_exc(cause, opc, run, vcpu);
-#endif
 			break;
 
 		default:
-			printk("RDHWR not supported\n");
-			er = EMULATE_FAIL;
-			break;
+			kvm_debug("RDHWR %#x not supported @ %p\n", rd, opc);
+			goto emulate_ri;
 		}
 	} else {
-		printk("Emulate RI not supported @ %p: %#x\n", opc, inst);
-		er = EMULATE_FAIL;
+		kvm_debug("Emulate RI not supported @ %p: %#x\n", opc, inst);
+		goto emulate_ri;
 	}
 
+	return EMULATE_DONE;
+
+emulate_ri:
 	/*
-	 * Rollback PC only if emulation was unsuccessful
+	 * Rollback PC (if in branch delay slot then the PC already points to
+	 * branch target), and pass the RI exception to the guest OS.
 	 */
-	if (er == EMULATE_FAIL) {
-		vcpu->arch.pc = curr_pc;
-	}
-	return er;
+	vcpu->arch.pc = curr_pc;
+	return kvm_mips_emulate_ri_exc(cause, opc, run, vcpu);
 }
 
 enum emulation_result