From: Marc Zyngier <marc.zyngier@arm.com>
To: linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Peter Maydell <peter.maydell@linaro.org>,
Christoffer Dall <christoffer.dall@linaro.org>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Robin Murphy <robin.murphy@arm.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Jon Masters <jcm@redhat.com>
Subject: [PATCH v2 11/16] arm64: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling
Date: Mon, 29 Jan 2018 17:45:54 +0000 [thread overview]
Message-ID: <20180129174559.1866-12-marc.zyngier@arm.com> (raw)
In-Reply-To: <20180129174559.1866-1-marc.zyngier@arm.com>
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.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
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 e4f37b9dd47c..f36464bd57c5 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>
@@ -64,10 +65,11 @@ 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
@@ -100,6 +102,20 @@ alternative_endif
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
--
2.14.2
WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <marc.zyngier@arm.com>
To: linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu
Cc: Mark Rutland <mark.rutland@arm.com>,
Peter Maydell <peter.maydell@linaro.org>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>, Jon Masters <jcm@redhat.com>,
Robin Murphy <robin.murphy@arm.com>,
Christoffer Dall <christoffer.dall@linaro.org>
Subject: [PATCH v2 11/16] arm64: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling
Date: Mon, 29 Jan 2018 17:45:54 +0000 [thread overview]
Message-ID: <20180129174559.1866-12-marc.zyngier@arm.com> (raw)
In-Reply-To: <20180129174559.1866-1-marc.zyngier@arm.com>
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.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
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 e4f37b9dd47c..f36464bd57c5 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>
@@ -64,10 +65,11 @@ 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
@@ -100,6 +102,20 @@ alternative_endif
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
--
2.14.2
WARNING: multiple messages have this Message-ID (diff)
From: marc.zyngier@arm.com (Marc Zyngier)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 11/16] arm64: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling
Date: Mon, 29 Jan 2018 17:45:54 +0000 [thread overview]
Message-ID: <20180129174559.1866-12-marc.zyngier@arm.com> (raw)
In-Reply-To: <20180129174559.1866-1-marc.zyngier@arm.com>
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.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
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 e4f37b9dd47c..f36464bd57c5 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>
@@ -64,10 +65,11 @@ 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
@@ -100,6 +102,20 @@ alternative_endif
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
--
2.14.2
next prev parent reply other threads:[~2018-01-29 17:55 UTC|newest]
Thread overview: 116+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-29 17:45 [PATCH v2 00/16] arm64: Add SMCCC v1.1 support and CVE-2017-5715 (Spectre variant 2) mitigation Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 17:45 ` [PATCH v2 01/16] arm64: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 17:45 ` [PATCH v2 02/16] arm: " Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 17:45 ` [PATCH v2 03/16] arm/arm64: KVM: Consolidate the PSCI include files Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 17:45 ` [PATCH v2 04/16] arm/arm64: KVM: Add PSCI_VERSION helper Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-30 13:15 ` Robin Murphy
2018-01-30 13:15 ` Robin Murphy
2018-01-30 14:52 ` Marc Zyngier
2018-01-30 14:52 ` Marc Zyngier
2018-01-29 17:45 ` [PATCH v2 05/16] arm/arm64: KVM: Add smccc accessors to PSCI code Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 17:45 ` [PATCH v2 06/16] arm/arm64: KVM: Implement PSCI 1.0 support Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 17:45 ` [PATCH v2 07/16] arm/arm64: KVM: Add PSCI version selection API Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-31 17:38 ` Andrew Jones
2018-01-31 17:38 ` Andrew Jones
2018-01-31 17:45 ` Marc Zyngier
2018-01-31 17:45 ` Marc Zyngier
2018-01-31 18:03 ` Andrew Jones
2018-01-31 18:03 ` Andrew Jones
2018-01-31 18:03 ` Andrew Jones
2018-01-31 18:36 ` Marc Zyngier
2018-01-31 18:36 ` Marc Zyngier
2018-01-31 19:15 ` Andrew Jones
2018-01-31 19:15 ` Andrew Jones
2018-01-31 18:11 ` kbuild test robot
2018-01-31 18:11 ` kbuild test robot
2018-01-29 17:45 ` [PATCH v2 08/16] arm/arm64: KVM: Advertise SMCCC v1.1 Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-30 0:23 ` Russell King - ARM Linux
2018-01-30 0:23 ` Russell King - ARM Linux
2018-01-30 12:28 ` Marc Zyngier
2018-01-30 12:28 ` Marc Zyngier
2018-01-30 12:28 ` Marc Zyngier
2018-01-29 17:45 ` [PATCH v2 09/16] arm/arm64: KVM: Turn kvm_psci_version into a static inline Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 17:45 ` [PATCH v2 10/16] arm64: KVM: Report SMCCC_ARCH_WORKAROUND_1 BP hardening support Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-30 12:38 ` Robin Murphy
2018-01-30 12:38 ` Robin Murphy
2018-01-29 17:45 ` Marc Zyngier [this message]
2018-01-29 17:45 ` [PATCH v2 11/16] arm64: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 17:45 ` [PATCH v2 12/16] firmware/psci: Expose PSCI conduit Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 17:55 ` Lorenzo Pieralisi
2018-01-29 17:55 ` Lorenzo Pieralisi
2018-01-29 17:45 ` [PATCH v2 13/16] firmware/psci: Expose SMCCC version through psci_ops Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 18:39 ` Lorenzo Pieralisi
2018-01-29 18:39 ` Lorenzo Pieralisi
2018-01-30 12:09 ` Marc Zyngier
2018-01-30 12:09 ` Marc Zyngier
2018-01-30 12:55 ` Robin Murphy
2018-01-30 12:55 ` Robin Murphy
2018-01-30 13:51 ` Marc Zyngier
2018-01-30 13:51 ` Marc Zyngier
2018-01-29 17:45 ` [PATCH v2 14/16] arm/arm64: smccc: Make function identifiers an unsigned quantity Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 17:45 ` [PATCH v2 15/16] arm/arm64: smccc: Implement SMCCC v1.1 inline primitive Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 19:07 ` Robin Murphy
2018-01-29 19:07 ` Robin Murphy
2018-01-30 8:54 ` Marc Zyngier
2018-01-30 8:54 ` Marc Zyngier
2018-01-29 21:45 ` Ard Biesheuvel
2018-01-29 21:45 ` Ard Biesheuvel
2018-01-30 12:27 ` Marc Zyngier
2018-01-30 12:27 ` Marc Zyngier
2018-01-30 12:29 ` Ard Biesheuvel
2018-01-30 12:29 ` Ard Biesheuvel
2018-01-30 12:29 ` Ard Biesheuvel
2018-01-29 17:45 ` [PATCH v2 16/16] arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 17:45 ` Marc Zyngier
2018-01-29 19:41 ` Ard Biesheuvel
2018-01-29 19:41 ` Ard Biesheuvel
2018-01-30 12:10 ` Marc Zyngier
2018-01-30 12:10 ` Marc Zyngier
2018-01-31 13:56 ` Hanjun Guo
2018-01-31 13:56 ` Hanjun Guo
2018-01-31 13:56 ` Hanjun Guo
2018-01-31 14:11 ` Marc Zyngier
2018-01-31 14:11 ` Marc Zyngier
2018-01-31 14:35 ` Ard Biesheuvel
2018-01-31 14:35 ` Ard Biesheuvel
2018-01-31 14:38 ` Ard Biesheuvel
2018-01-31 14:38 ` Ard Biesheuvel
2018-01-31 15:05 ` Marc Zyngier
2018-01-31 15:05 ` Marc Zyngier
2018-02-01 2:40 ` Hanjun Guo
2018-02-01 2:40 ` Hanjun Guo
2018-02-01 6:52 ` Hanjun Guo
2018-02-01 6:52 ` Hanjun Guo
2018-02-01 6:52 ` Hanjun Guo
2018-02-01 8:53 ` Marc Zyngier
2018-02-01 8:53 ` Marc Zyngier
2018-02-02 3:43 ` Hanjun Guo
2018-02-02 3:43 ` Hanjun Guo
2018-06-09 13:22 ` [PATCH v2 00/16] arm64: Add SMCCC v1.1 support and CVE-2017-5715 (Spectre variant 2) mitigation Jon Masters
2018-06-09 13:22 ` Jon Masters
2018-06-09 14:06 ` Marc Zyngier
2018-06-09 14:06 ` Marc Zyngier
2018-06-09 14:06 ` Marc Zyngier
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