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-rw-r--r--arch/arm64/kvm/hyp-init.S48
1 files changed, 46 insertions, 2 deletions
diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S
index 7d8747c..a873a6d 100644
--- 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
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