2017-04-24 18:43:24

by David Daney

[permalink] [raw]
Subject: [PATCH 0/2] arm64: Workaround for Thunder KVM hang issues.

We have discovered in rare circumstances, guest execution may result
in host not receiving one or more interrupts. This does not otherwise
affect guest or host execution and/or isolation.


David Daney (2):
arm64: Add MIDR values for Cavium cn83XX SoCs
arm64: Add workaround for Cavium Thunder erratum 30115

Documentation/arm64/silicon-errata.txt | 1 +
arch/arm64/Kconfig | 11 +++++++++++
arch/arm64/include/asm/cpucaps.h | 3 ++-
arch/arm64/include/asm/cputype.h | 2 ++
arch/arm64/kernel/cpu_errata.c | 21 +++++++++++++++++++++
arch/arm64/kvm/hyp/switch.c | 9 +++++++++
6 files changed, 46 insertions(+), 1 deletion(-)

--
2.7.4


2017-04-24 18:43:37

by David Daney

[permalink] [raw]
Subject: [PATCH 2/2] arm64: Add workaround for Cavium Thunder erratum 30115

Some Cavium Thunder CPUs suffer a problem where a KVM guest may
inadvertently cause the host kernel to quit receiving interrupts.

The workaround is to toggle the group-1 interrupt enable on each exit
from the guest.

Signed-off-by: David Daney <[email protected]>
---
Documentation/arm64/silicon-errata.txt | 1 +
arch/arm64/Kconfig | 11 +++++++++++
arch/arm64/include/asm/cpucaps.h | 3 ++-
arch/arm64/kernel/cpu_errata.c | 21 +++++++++++++++++++++
arch/arm64/kvm/hyp/switch.c | 9 +++++++++
5 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt
index 10f2ddd..f5f93dc 100644
--- a/Documentation/arm64/silicon-errata.txt
+++ b/Documentation/arm64/silicon-errata.txt
@@ -62,6 +62,7 @@ stable kernels.
| Cavium | ThunderX GICv3 | #23154 | CAVIUM_ERRATUM_23154 |
| Cavium | ThunderX Core | #27456 | CAVIUM_ERRATUM_27456 |
| Cavium | ThunderX SMMUv2 | #27704 | N/A |
+| Cavium | ThunderX Core | #30115 | CAVIUM_ERRATUM_30115 |
| | | | |
| Freescale/NXP | LS2080A/LS1043A | A-008585 | FSL_ERRATUM_A008585 |
| | | | |
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index e7f043e..fe29277 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -480,6 +480,17 @@ config CAVIUM_ERRATUM_27456

If unsure, say Y.

+config CAVIUM_ERRATUM_30115
+ bool "Cavium erratum 30115: Guest may disable interrupts in host"
+ default y
+ help
+ On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
+ 1.2, and T83 Pass 1.0, KVM guest execution may disable
+ interrupts in host. The fix is to reenable group 1
+ interrupts when returning to host mode.
+
+ If unsure, say Y.
+
config QCOM_FALKOR_ERRATUM_1003
bool "Falkor E1003: Incorrect translation due to ASID change"
default y
diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index b3aab8a..8d2272c 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -38,7 +38,8 @@
#define ARM64_WORKAROUND_REPEAT_TLBI 17
#define ARM64_WORKAROUND_QCOM_FALKOR_E1003 18
#define ARM64_WORKAROUND_858921 19
+#define ARM64_WORKAROUND_CAVIUM_30115 20

-#define ARM64_NCAPS 20
+#define ARM64_NCAPS 21

#endif /* __ASM_CPUCAPS_H */
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 2ed2a76..0e27f86 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -133,6 +133,27 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
MIDR_RANGE(MIDR_THUNDERX_81XX, 0x00, 0x00),
},
#endif
+#ifdef CONFIG_CAVIUM_ERRATUM_30115
+ {
+ /* Cavium ThunderX, T88 pass 1.x - 2.2 */
+ .desc = "Cavium erratum 30115",
+ .capability = ARM64_WORKAROUND_CAVIUM_30115,
+ MIDR_RANGE(MIDR_THUNDERX, 0x00,
+ (1 << MIDR_VARIANT_SHIFT) | 2),
+ },
+ {
+ /* Cavium ThunderX, T81 pass 1.0 - 1.2 */
+ .desc = "Cavium erratum 30115",
+ .capability = ARM64_WORKAROUND_CAVIUM_30115,
+ MIDR_RANGE(MIDR_THUNDERX_81XX, 0x00, 0x02),
+ },
+ {
+ /* Cavium ThunderX, T83 pass 1.0 */
+ .desc = "Cavium erratum 30115",
+ .capability = ARM64_WORKAROUND_CAVIUM_30115,
+ MIDR_RANGE(MIDR_THUNDERX_83XX, 0x00, 0x00),
+ },
+#endif
{
.desc = "Mismatched cache line size",
.capability = ARM64_MISMATCHED_CACHE_LINE_SIZE,
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index aede165..c174b5f 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -17,11 +17,13 @@

#include <linux/types.h>
#include <linux/jump_label.h>
+#include <linux/irqchip/arm-gic-v3.h>

#include <asm/kvm_asm.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_hyp.h>
#include <asm/fpsimd.h>
+#include <asm/cpufeature.h>

static bool __hyp_text __fpsimd_enabled_nvhe(void)
{
@@ -166,6 +168,13 @@ static void __hyp_text __vgic_save_state(struct kvm_vcpu *vcpu)
__vgic_v2_save_state(vcpu);

write_sysreg(read_sysreg(hcr_el2) & ~HCR_INT_OVERRIDE, hcr_el2);
+
+#ifdef CONFIG_CAVIUM_ERRATUM_30115
+ if (cpus_have_const_cap(ARM64_WORKAROUND_CAVIUM_30115)) {
+ gic_write_grpen1(0);
+ gic_write_grpen1(1);
+ }
+#endif
}

static void __hyp_text __vgic_restore_state(struct kvm_vcpu *vcpu)
--
2.7.4

2017-04-24 18:43:12

by David Daney

[permalink] [raw]
Subject: [PATCH 1/2] arm64: Add MIDR values for Cavium cn83XX SoCs

Signed-off-by: David Daney <[email protected]>
---
arch/arm64/include/asm/cputype.h | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index 0984d1b..235e77d 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -86,6 +86,7 @@

#define CAVIUM_CPU_PART_THUNDERX 0x0A1
#define CAVIUM_CPU_PART_THUNDERX_81XX 0x0A2
+#define CAVIUM_CPU_PART_THUNDERX_83XX 0x0A3

#define BRCM_CPU_PART_VULCAN 0x516

@@ -96,6 +97,7 @@
#define MIDR_CORTEX_A73 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A73)
#define MIDR_THUNDERX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX)
#define MIDR_THUNDERX_81XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_81XX)
+#define MIDR_THUNDERX_83XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_83XX)
#define MIDR_QCOM_FALKOR_V1 MIDR_CPU_MODEL(ARM_CPU_IMP_QCOM, QCOM_CPU_PART_FALKOR_V1)

#ifndef __ASSEMBLY__
--
2.7.4