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authorMarc Zyngier <marc.zyngier@arm.com>2017-06-06 19:08:33 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-06-14 15:05:56 +0200
commitb9824dd75fcf6d9f10e8df08b237948d1802d5fe (patch)
tree891d518c9bf410c4cda3a09d49c1eb797f75279d /arch
parent19c9a115085edc6e2f1ee8e7c30600ba2fa932f4 (diff)
arm64: KVM: Preserve RES1 bits in SCTLR_EL2
commit d68c1f7fd1b7148dab5fe658321d511998969f2d upstream. __do_hyp_init has the rather bad habit of ignoring RES1 bits and writing them back as zero. On a v8.0-8.2 CPU, this doesn't do anything bad, but may end-up being pretty nasty on future revisions of the architecture. Let's preserve those bits so that we don't have to fix this later on. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/include/asm/sysreg.h4
-rw-r--r--arch/arm64/kvm/hyp-init.S10
2 files changed, 10 insertions, 4 deletions
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 6c80b3699cb8..7393cc767edb 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -94,6 +94,10 @@
#define SCTLR_ELx_A (1 << 1)
#define SCTLR_ELx_M 1
+#define SCTLR_EL2_RES1 ((1 << 4) | (1 << 5) | (1 << 11) | (1 << 16) | \
+ (1 << 16) | (1 << 18) | (1 << 22) | (1 << 23) | \
+ (1 << 28) | (1 << 29))
+
#define SCTLR_ELx_FLAGS (SCTLR_ELx_M | SCTLR_ELx_A | SCTLR_ELx_C | \
SCTLR_ELx_SA | SCTLR_ELx_I)
diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S
index 6b29d3d9e1f2..4e460d973560 100644
--- a/arch/arm64/kvm/hyp-init.S
+++ b/arch/arm64/kvm/hyp-init.S
@@ -102,10 +102,12 @@ __do_hyp_init:
tlbi alle2
dsb sy
- mrs x4, sctlr_el2
- and x4, x4, #SCTLR_ELx_EE // preserve endianness of EL2
- ldr x5, =SCTLR_ELx_FLAGS
- orr x4, x4, x5
+ /*
+ * Preserve all the RES1 bits while setting the default flags,
+ * as well as the EE bit on BE.
+ */
+ ldr x4, =(SCTLR_EL2_RES1 | SCTLR_ELx_FLAGS)
+CPU_BE( orr x4, x4, #SCTLR_ELx_EE)
msr sctlr_el2, x4
isb