KVM: PPC: Book3S HV: Sanitize special-purpose register values on guest exit

[uclinux-h8/linux.git] / arch / powerpc / kvm / book3s_hv_rmhandlers.S

diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 6ee26de..25ae2c9 100644 (file)
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1370,6 +1370,20 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
        std     r6, VCPU_ACOP(r9)
        stw     r7, VCPU_GUEST_PID(r9)
        std     r8, VCPU_WORT(r9)
+       /*
+        * Restore various registers to 0, where non-zero values
+        * set by the guest could disrupt the host.
+        */
+       li      r0, 0
+       mtspr   SPRN_IAMR, r0
+       mtspr   SPRN_CIABR, r0
+       mtspr   SPRN_DAWRX, r0
+       mtspr   SPRN_TCSCR, r0
+       mtspr   SPRN_WORT, r0
+       /* Set MMCRS to 1<<31 to freeze and disable the SPMC counters */
+       li      r0, 1
+       sldi    r0, r0, 31
+       mtspr   SPRN_MMCRS, r0
 8:
 
        /* Save and reset AMR and UAMOR before turning on the MMU */