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authorAndrew Scull <ascull@google.com>2020-07-06 10:52:59 +0100
committerMarc Zyngier <maz@kernel.org>2020-07-06 11:47:02 +0100
commitb9e10d4a6c9f5cbe6369ce2c17ebc67d2e5a4be5 (patch)
tree93be99720bd75cc669b93555425d9ce4a5ab049c
parent146f76cc84b787c4eec6ed73ebeec708a06e4ae4 (diff)
downloadlinux-stericsson-b9e10d4a6c9f5cbe6369ce2c17ebc67d2e5a4be5.tar.gz
KVM: arm64: Stop clobbering x0 for HVC_SOFT_RESTART
HVC_SOFT_RESTART is given values for x0-2 that it should installed before exiting to the new address so should not set x0 to stub HVC success or failure code. Fixes: af42f20480bf1 ("arm64: hyp-stub: Zero x0 on successful stub handling") Cc: stable@vger.kernel.org Signed-off-by: Andrew Scull <ascull@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200706095259.1338221-1-ascull@google.com
-rw-r--r--arch/arm64/kvm/hyp-init.S11
1 files changed, 7 insertions, 4 deletions
diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S
index 6e6ed5581eed..e76c0e89d48e 100644
--- a/arch/arm64/kvm/hyp-init.S
+++ b/arch/arm64/kvm/hyp-init.S
@@ -136,11 +136,15 @@ SYM_CODE_START(__kvm_handle_stub_hvc)
1: cmp x0, #HVC_RESET_VECTORS
b.ne 1f
-reset:
+
/*
- * Reset kvm back to the hyp stub. Do not clobber x0-x4 in
- * case we coming via HVC_SOFT_RESTART.
+ * Set the HVC_RESET_VECTORS return code before entering the common
+ * path so that we do not clobber x0-x2 in case we are coming via
+ * HVC_SOFT_RESTART.
*/
+ mov x0, xzr
+reset:
+ /* Reset kvm back to the hyp stub. */
mrs x5, sctlr_el2
mov_q x6, SCTLR_ELx_FLAGS
bic x5, x5, x6 // Clear SCTL_M and etc
@@ -151,7 +155,6 @@ reset:
/* Install stub vectors */
adr_l x5, __hyp_stub_vectors
msr vbar_el2, x5
- mov x0, xzr
eret
1: /* Bad stub call */