| Message ID | 1445894043-31519-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S index c3ca89c..cbaa8bc 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -946,13 +946,15 @@ ENTRY(__kvm_vcpu_run) // Guest context add x2, x0, #VCPU_CONTEXT + // We must restore the 32-bit state before the sysregs, thanks + // to Cortex-A57 erratum #852523. + restore_guest_32bit_state bl __restore_sysregs bl __restore_fpsimd skip_debug_state x3, 1f bl __restore_debug 1: - restore_guest_32bit_state restore_guest_regs // That's it, no more messing around.
This is a note to let you know that I have just added a patch titled KVM: arm64: add workaround for Cortex-A57 erratum #852523 to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.19.8-ckt9. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 88645476818b8aab2403d70cee40f8dd259044c7 Mon Sep 17 00:00:00 2001 From: Will Deacon <will.deacon@arm.com> Date: Mon, 14 Sep 2015 16:06:03 +0100 Subject: KVM: arm64: add workaround for Cortex-A57 erratum #852523 commit 43297dda0a51e4ffed0888ce727c218cfb7474b6 upstream. When restoring the system register state for an AArch32 guest at EL2, writes to DACR32_EL2 may not be correctly synchronised by Cortex-A57, which can lead to the guest effectively running with junk in the DACR and running into unexpected domain faults. This patch works around the issue by re-ordering our restoration of the AArch32 register aliases so that they happen before the AArch64 system registers. Ensuring that the registers are restored in this order guarantees that they will be correctly synchronised by the core. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- arch/arm64/kvm/hyp.S | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) -- 1.9.1