| Message ID | 1445979920-30959-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index c68cca5..0ddb13a 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -203,6 +203,11 @@ CPU_LE( movk x0, #0x30d0, lsl #16 ) // Clear EE and E0E on LE systems msr hstr_el2, xzr // Disable CP15 traps to EL2 #endif + /* EL2 debug */ + mrs x0, pmcr_el0 // Disable debug access traps + ubfx x0, x0, #11, #5 // to EL2 and allow access to + msr mdcr_el2, x0 // all PMU counters from EL1 + /* Stage-2 translation */ msr vttbr_el2, xzr
This is a note to let you know that I have just added a patch titled arm64: head.S: initialise mdcr_el2 in el2_setup to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue This patch is scheduled to be released in version 3.13.11-ckt29. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.13.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 01894534325fbd63013a8677a9b8ce662bf037f0 Mon Sep 17 00:00:00 2001 From: Will Deacon <will.deacon@arm.com> Date: Wed, 2 Sep 2015 18:49:28 +0100 Subject: arm64: head.S: initialise mdcr_el2 in el2_setup commit d10bcd473301888f957ec4b6b12aa3621be78d59 upstream. When entering the kernel at EL2, we fail to initialise the MDCR_EL2 register which controls debug access and PMU capabilities at EL1. This patch ensures that the register is initialised so that all traps are disabled and all the PMU counters are available to the host. When a guest is scheduled, KVM takes care to configure trapping appropriately. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- arch/arm64/kernel/head.S | 5 +++++ 1 file changed, 5 insertions(+) -- 1.9.1