From: Mark Rutland <mark.rutland@arm.com>
To: stable@vger.kernel.org
Cc: mark.brown@linaro.org, ard.biesheuvel@linaro.org,
marc.zyngier@arm.com, will.deacon@arm.com,
catalin.marinas@arm.com, ghackmann@google.com,
shankerd@codeaurora.org
Subject: [PATCH v4.9.y 36/42] arm64: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling
Date: Thu, 12 Apr 2018 12:11:32 +0100 [thread overview]
Message-ID: <20180412111138.40990-37-mark.rutland@arm.com> (raw)
In-Reply-To: <20180412111138.40990-1-mark.rutland@arm.com>
From: Marc Zyngier <marc.zyngier@arm.com>
commit f72af90c3783d924337624659b43e2d36f1b36b4 upstream.
We want SMCCC_ARCH_WORKAROUND_1 to be fast. As fast as possible.
So let's intercept it as early as we can by testing for the
function call number as soon as we've identified a HVC call
coming from the guest.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com> [v4.9 backport]
---
arch/arm64/kvm/hyp/hyp-entry.S | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S
index 4e92399f7105..4e9d50c3e658 100644
--- a/arch/arm64/kvm/hyp/hyp-entry.S
+++ b/arch/arm64/kvm/hyp/hyp-entry.S
@@ -15,6 +15,7 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <linux/arm-smccc.h>
#include <linux/linkage.h>
#include <asm/alternative.h>
@@ -79,10 +80,11 @@ alternative_endif
lsr x0, x1, #ESR_ELx_EC_SHIFT
cmp x0, #ESR_ELx_EC_HVC64
+ ccmp x0, #ESR_ELx_EC_HVC32, #4, ne
b.ne el1_trap
- mrs x1, vttbr_el2 // If vttbr is valid, the 64bit guest
- cbnz x1, el1_trap // called HVC
+ mrs x1, vttbr_el2 // If vttbr is valid, the guest
+ cbnz x1, el1_hvc_guest // called HVC
/* Here, we're pretty sure the host called HVC. */
ldp x0, x1, [sp], #16
@@ -101,6 +103,20 @@ alternative_endif
2: eret
+el1_hvc_guest:
+ /*
+ * Fastest possible path for ARM_SMCCC_ARCH_WORKAROUND_1.
+ * The workaround has already been applied on the host,
+ * so let's quickly get back to the guest. We don't bother
+ * restoring x1, as it can be clobbered anyway.
+ */
+ ldr x1, [sp] // Guest's x0
+ eor w1, w1, #ARM_SMCCC_ARCH_WORKAROUND_1
+ cbnz w1, el1_trap
+ mov x0, x1
+ add sp, sp, #16
+ eret
+
el1_trap:
/*
* x0: ESR_EC
--
2.11.0
next prev parent reply other threads:[~2018-04-12 11:13 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-12 11:10 [PATCH v4.9.y 00/42] arm64 spectre patches Mark Rutland
2018-04-12 11:10 ` [PATCH v4.9.y 01/42] arm64: barrier: Add CSDB macros to control data-value prediction Mark Rutland
2018-04-12 11:10 ` [PATCH v4.9.y 02/42] arm64: Implement array_index_mask_nospec() Mark Rutland
2018-04-12 11:10 ` [PATCH v4.9.y 03/42] arm64: move TASK_* definitions to <asm/processor.h> Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 04/42] arm64: Make USER_DS an inclusive limit Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 05/42] arm64: Use pointer masking to limit uaccess speculation Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 06/42] arm64: entry: Ensure branch through syscall table is bounded under speculation Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 07/42] arm64: uaccess: Prevent speculative use of the current addr_limit Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 08/42] arm64: uaccess: Don't bother eliding access_ok checks in __{get, put}_user Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 09/42] arm64: uaccess: Mask __user pointers for __arch_{clear, copy_*}_user Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 10/42] arm64: futex: Mask __user pointers prior to dereference Mark Rutland
2018-04-17 12:10 ` Greg KH
2018-04-18 10:56 ` Mark Rutland
2018-04-19 7:02 ` Greg KH
2018-04-12 11:11 ` [PATCH v4.9.y 11/42] arm64: cpufeature: __this_cpu_has_cap() shouldn't stop early Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 12/42] arm64: Run enable method for errata work arounds on late CPUs Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 13/42] arm64: cpufeature: Pass capability structure to ->enable callback Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 14/42] drivers/firmware: Expose psci_get_version through psci_ops structure Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 15/42] arm64: Factor out TTBR0_EL1 post-update workaround into a specific asm macro Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 16/42] arm64: Move post_ttbr_update_workaround to C code Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 17/42] arm64: Add skeleton to harden the branch predictor against aliasing attacks Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 18/42] arm64: Move BP hardening to check_and_switch_context Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 19/42] mm: Introduce lm_alias Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 20/42] arm64: KVM: Use per-CPU vector when BP hardening is enabled Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 21/42] arm64: entry: Apply BP hardening for high-priority synchronous exceptions Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 22/42] arm64: entry: Apply BP hardening for suspicious interrupts from EL0 Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 23/42] arm64: cputype: Add missing MIDR values for Cortex-A72 and Cortex-A75 Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 24/42] arm64: cpu_errata: Allow an erratum to be match for all revisions of a core Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 25/42] arm64: Implement branch predictor hardening for affected Cortex-A CPUs Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 26/42] arm64: Branch predictor hardening for Cavium ThunderX2 Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 27/42] arm64: KVM: Increment PC after handling an SMC trap Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 28/42] arm/arm64: KVM: Consolidate the PSCI include files Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 29/42] arm/arm64: KVM: Add PSCI_VERSION helper Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 30/42] arm/arm64: KVM: Add smccc accessors to PSCI code Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 31/42] arm/arm64: KVM: Implement PSCI 1.0 support Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 32/42] arm/arm64: KVM: Advertise SMCCC v1.1 Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 33/42] arm64: KVM: Make PSCI_VERSION a fast path Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 34/42] arm/arm64: KVM: Turn kvm_psci_version into a static inline Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 35/42] arm64: KVM: Report SMCCC_ARCH_WORKAROUND_1 BP hardening support Mark Rutland
2018-04-12 11:11 ` Mark Rutland [this message]
2018-04-12 11:11 ` [PATCH v4.9.y 37/42] firmware/psci: Expose PSCI conduit Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 38/42] firmware/psci: Expose SMCCC version through psci_ops Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 39/42] arm/arm64: smccc: Make function identifiers an unsigned quantity Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 40/42] arm/arm64: smccc: Implement SMCCC v1.1 inline primitive Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 41/42] arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support Mark Rutland
2018-04-12 11:11 ` [PATCH v4.9.y 42/42] arm64: Kill PSCI_GET_VERSION as a variant-2 workaround Mark Rutland
2018-04-12 16:39 ` [PATCH v4.9.y 00/42] arm64 spectre patches Greg Hackmann
2018-04-17 12:15 ` Greg KH
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