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authorJames Morse <james.morse@arm.com>2019-06-18 16:17:34 +0100
committerMarc Zyngier <marc.zyngier@arm.com>2019-07-05 13:03:29 +0100
commit3dbf100b0b10e91d65bd83b91cee3ef61f1b96c4 (patch)
treec02ee88d3b53d1dd082de67bc70f33048ea82426 /arch/arm64/include
parent2b68a2a963a157f024c67c0697b16f5f792c8a35 (diff)
downloadlinux-3dbf100b0b10e91d65bd83b91cee3ef61f1b96c4.tar.bz2
KVM: arm64: Abstract the size of the HYP vectors pre-amble
The EL2 vector hardening feature causes KVM to generate vectors for each type of CPU present in the system. The generated sequences already do some of the early guest-exit work (i.e. saving registers). To avoid duplication the generated vectors branch to the original vector just after the preamble. This size is hard coded. Adding new instructions to the HYP vector causes strange side effects, which are difficult to debug as the affected code is patched in at runtime. Add KVM_VECTOR_PREAMBLE to tell kvm_patch_vector_branch() how big the preamble is. The valid_vect macro can then validate this at build time. Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm64/include')
-rw-r--r--arch/arm64/include/asm/kvm_asm.h6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 2ca437ef59fa..388e1b520618 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -30,6 +30,12 @@
{ARM_EXCEPTION_TRAP, "TRAP" }, \
{ARM_EXCEPTION_HYP_GONE, "HYP_GONE" }
+/*
+ * Size of the HYP vectors preamble. kvm_patch_vector_branch() generates code
+ * that jumps over this.
+ */
+#define KVM_VECTOR_PREAMBLE (1 * AARCH64_INSN_SIZE)
+
#ifndef __ASSEMBLY__
#include <linux/mm.h>