4.19-stable patches

added patches:
	kvm-arm64-synchronize-sysreg-state-on-injecting-an-aarch32-exception.patch

diff --git a/queue-4.19/kvm-arm64-synchronize-sysreg-state-on-injecting-an-aarch32-exception.patch b/queue-4.19/kvm-arm64-synchronize-sysreg-state-on-injecting-an-aarch32-exception.patch
new file mode 100644 (file)
index 0000000..c5747f0
--- /dev/null
+++ b/queue-4.19/kvm-arm64-synchronize-sysreg-state-on-injecting-an-aarch32-exception.patch
@@ -0,0 +1,112 @@
+From 0370964dd3ff7d3d406f292cb443a927952cbd05 Mon Sep 17 00:00:00 2001
+From: Marc Zyngier <maz@kernel.org>
+Date: Tue, 9 Jun 2020 08:50:29 +0100
+Subject: KVM: arm64: Synchronize sysreg state on injecting an AArch32 exception
+
+From: Marc Zyngier <maz@kernel.org>
+
+commit 0370964dd3ff7d3d406f292cb443a927952cbd05 upstream.
+
+On a VHE system, the EL1 state is left in the CPU most of the time,
+and only syncronized back to memory when vcpu_put() is called (most
+of the time on preemption).
+
+Which means that when injecting an exception, we'd better have a way
+to either:
+(1) write directly to the EL1 sysregs
+(2) synchronize the state back to memory, and do the changes there
+
+For an AArch64, we already do (1), so we are safe. Unfortunately,
+doing the same thing for AArch32 would be pretty invasive. Instead,
+we can easily implement (2) by calling the put/load architectural
+backends, and keep preemption disabled. We can then reload the
+state back into EL1.
+
+Cc: stable@vger.kernel.org
+Reported-by: James Morse <james.morse@arm.com>
+Signed-off-by: Marc Zyngier <maz@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/arm/include/asm/kvm_host.h   |    2 ++
+ arch/arm64/include/asm/kvm_host.h |    2 ++
+ virt/kvm/arm/aarch32.c            |   28 ++++++++++++++++++++++++++++
+ 3 files changed, 32 insertions(+)
+
+--- a/arch/arm/include/asm/kvm_host.h
++++ b/arch/arm/include/asm/kvm_host.h
+@@ -364,4 +364,6 @@ static inline void kvm_vcpu_put_sysregs(
+ struct kvm *kvm_arch_alloc_vm(void);
+ void kvm_arch_free_vm(struct kvm *kvm);
+ 
++#define kvm_arm_vcpu_loaded(vcpu)     (false)
++
+ #endif /* __ARM_KVM_HOST_H__ */
+--- a/arch/arm64/include/asm/kvm_host.h
++++ b/arch/arm64/include/asm/kvm_host.h
+@@ -537,4 +537,6 @@ void kvm_vcpu_put_sysregs(struct kvm_vcp
+ struct kvm *kvm_arch_alloc_vm(void);
+ void kvm_arch_free_vm(struct kvm *kvm);
+ 
++#define kvm_arm_vcpu_loaded(vcpu)     ((vcpu)->arch.sysregs_loaded_on_cpu)
++
+ #endif /* __ARM64_KVM_HOST_H__ */
+--- a/virt/kvm/arm/aarch32.c
++++ b/virt/kvm/arm/aarch32.c
+@@ -44,6 +44,26 @@ static const u8 return_offsets[8][2] = {
+       [7] = { 4, 4 },         /* FIQ, unused */
+ };
+ 
++static bool pre_fault_synchronize(struct kvm_vcpu *vcpu)
++{
++      preempt_disable();
++      if (kvm_arm_vcpu_loaded(vcpu)) {
++              kvm_arch_vcpu_put(vcpu);
++              return true;
++      }
++
++      preempt_enable();
++      return false;
++}
++
++static void post_fault_synchronize(struct kvm_vcpu *vcpu, bool loaded)
++{
++      if (loaded) {
++              kvm_arch_vcpu_load(vcpu, smp_processor_id());
++              preempt_enable();
++      }
++}
++
+ /*
+  * When an exception is taken, most CPSR fields are left unchanged in the
+  * handler. However, some are explicitly overridden (e.g. M[4:0]).
+@@ -166,7 +186,10 @@ static void prepare_fault32(struct kvm_v
+ 
+ void kvm_inject_undef32(struct kvm_vcpu *vcpu)
+ {
++      bool loaded = pre_fault_synchronize(vcpu);
++
+       prepare_fault32(vcpu, PSR_AA32_MODE_UND, 4);
++      post_fault_synchronize(vcpu, loaded);
+ }
+ 
+ /*
+@@ -179,6 +202,9 @@ static void inject_abt32(struct kvm_vcpu
+       u32 vect_offset;
+       u32 *far, *fsr;
+       bool is_lpae;
++      bool loaded;
++
++      loaded = pre_fault_synchronize(vcpu);
+ 
+       if (is_pabt) {
+               vect_offset = 12;
+@@ -202,6 +228,8 @@ static void inject_abt32(struct kvm_vcpu
+               /* no need to shuffle FS[4] into DFSR[10] as its 0 */
+               *fsr = DFSR_FSC_EXTABT_nLPAE;
+       }
++
++      post_fault_synchronize(vcpu, loaded);
+ }
+ 
+ void kvm_inject_dabt32(struct kvm_vcpu *vcpu, unsigned long addr)

diff --git a/queue-4.19/series b/queue-4.19/series
index d43acab5cbc67b9fd01df5c357591934d77b4123..18e741246003450da8f702b79d66ae1e94a112ed 100644 (file)
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -89,3 +89,4 @@ mmc-sdhci-msm-clear-tuning-done-flag-while-hs400-tuning.patch
 arm-dts-at91-sama5d2_ptc_ek-fix-sdmmc0-node-description.patch
 mmc-sdio-fix-potential-null-pointer-error-in-mmc_sdio_init_card.patch
 xen-pvcalls-back-test-for-errors-when-calling-backend_connect.patch
+kvm-arm64-synchronize-sysreg-state-on-injecting-an-aarch32-exception.patch