Merge branch 'for-linus' of git://git.kernel.dk/linux-block

[karo-tx-linux.git] / arch / arm64 / kvm / hyp-init.S

diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S
index 7d8747c6427cdf474d1aac9b70c7abe51aece035..a873a6d8be908da6549fb5fa02a437de11d4f91c 100644 (file)
--- a/arch/arm64/kvm/hyp-init.S
+++ b/arch/arm64/kvm/hyp-init.S
@@ -21,6 +21,7 @@
 #include <asm/kvm_arm.h>
 #include <asm/kvm_mmu.h>
 #include <asm/pgtable-hwdef.h>
+#include <asm/sysreg.h>
 
        .text
        .pushsection    .hyp.idmap.text, "ax"
@@ -103,8 +104,8 @@ __do_hyp_init:
        dsb     sy
 
        mrs     x4, sctlr_el2
-       and     x4, x4, #SCTLR_EL2_EE   // preserve endianness of EL2
-       ldr     x5, =SCTLR_EL2_FLAGS
+       and     x4, x4, #SCTLR_ELx_EE   // preserve endianness of EL2
+       ldr     x5, =SCTLR_ELx_FLAGS
        orr     x4, x4, x5
        msr     sctlr_el2, x4
        isb
@@ -138,6 +139,49 @@ merged:
        eret
 ENDPROC(__kvm_hyp_init)
 
+       /*
+        * Reset kvm back to the hyp stub. This is the trampoline dance in
+        * reverse. If kvm used an extended idmap, __extended_idmap_trampoline
+        * calls this code directly in the idmap. In this case switching to the
+        * boot tables is a no-op.
+        *
+        * x0: HYP boot pgd
+        * x1: HYP phys_idmap_start
+        */
+ENTRY(__kvm_hyp_reset)
+       /* We're in trampoline code in VA, switch back to boot page tables */
+       msr     ttbr0_el2, x0
+       isb
+
+       /* Ensure the PA branch doesn't find a stale tlb entry or stale code. */
+       ic      iallu
+       tlbi    alle2
+       dsb     sy
+       isb
+
+       /* Branch into PA space */
+       adr     x0, 1f
+       bfi     x1, x0, #0, #PAGE_SHIFT
+       br      x1
+
+       /* We're now in idmap, disable MMU */
+1:     mrs     x0, sctlr_el2
+       ldr     x1, =SCTLR_ELx_FLAGS
+       bic     x0, x0, x1              // Clear SCTL_M and etc
+       msr     sctlr_el2, x0
+       isb
+
+       /* Invalidate the old TLBs */
+       tlbi    alle2
+       dsb     sy
+
+       /* Install stub vectors */
+       adr_l   x0, __hyp_stub_vectors
+       msr     vbar_el2, x0
+
+       eret
+ENDPROC(__kvm_hyp_reset)
+
        .ltorg
 
        .popsection