summaryrefslogtreecommitdiffstats
path: root/arch/arm64/kernel/hyp-stub.S
diff options
context:
space:
mode:
authorJames Morse <james.morse@arm.com>2016-04-27 18:47:04 +0200
committerWill Deacon <will.deacon@arm.com>2016-04-28 13:05:46 +0200
commitc94b0cf28281d483c8b43b4874fcb7ab14ade1b1 (patch)
tree9a1b36f51a6dc5d2886f36454a1e3ac63eae640f /arch/arm64/kernel/hyp-stub.S
parentarm64: hyp/kvm: Make hyp-stub extensible (diff)
downloadlinux-c94b0cf28281d483c8b43b4874fcb7ab14ade1b1.tar.xz
linux-c94b0cf28281d483c8b43b4874fcb7ab14ade1b1.zip
arm64: hyp/kvm: Make hyp-stub reject kvm_call_hyp()
A later patch implements kvm_arch_hardware_disable(), to remove kvm from el2, and re-instate the hyp-stub. This can happen while guests are running, particularly when kvm_reboot() calls kvm_arch_hardware_disable() on each cpu. This can interrupt a guest, remove kvm, then allow the guest to be scheduled again. This causes kvm_call_hyp() to be run against the hyp-stub. Change the hyp-stub to return a new exception type when this happens, and add code to kvm's handle_exit() to tell userspace we failed to enter the guest. Signed-off-by: James Morse <james.morse@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel/hyp-stub.S')
-rw-r--r--arch/arm64/kernel/hyp-stub.S5
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S
index 894fb40fb378..8727f4490772 100644
--- a/arch/arm64/kernel/hyp-stub.S
+++ b/arch/arm64/kernel/hyp-stub.S
@@ -23,6 +23,7 @@
#include <asm/assembler.h>
#include <asm/kvm_arm.h>
+#include <asm/kvm_asm.h>
#include <asm/ptrace.h>
#include <asm/virt.h>
@@ -70,8 +71,8 @@ el1_sync:
msr vbar_el2, x1
b 9f
- /* Unrecognised call type */
-2: mov x0, xzr
+ /* Someone called kvm_call_hyp() against the hyp-stub... */
+2: mov x0, #ARM_EXCEPTION_HYP_GONE
9: eret
ENDPROC(el1_sync)