Hi Mark,
On 2020-02-10 11:47, Mark Rutland wrote:
With VHE, running a vCPU always requires the sequence:
1. kvm_arm_vhe_guest_enter();
2. kvm_vcpu_run_vhe();
3. kvm_arm_vhe_guest_exit()
... and as we invoke this from the shared arm/arm64 KVM code, 32-bit
arm
has to provide stubs for all three functions.
To simplify the common code, and make it easier to make further
modifications to the arm64-specific portions in the near future, let's
fold kvm_arm_vhe_guest_enter() and kvm_arm_vhe_guest_exit() into
kvm_vcpu_run_vhe().
The 32-bit stubs for kvm_arm_vhe_guest_enter() and
kvm_arm_vhe_guest_exit() are removed, as they are no longer used. The
32-bit stub for kvm_vcpu_run_vhe() is left as-is.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: James Morse <james.morse@xxxxxxx>
Cc: Julien Thierry <julien.thierry.kdev@xxxxxxxxx>
Cc: Marc Zyngier <maz@xxxxxxxxxx>
Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: kvmarm@xxxxxxxxxxxxxxxxxxxxx
---
arch/arm/include/asm/kvm_host.h | 3 ---
arch/arm64/include/asm/kvm_host.h | 32
--------------------------------
arch/arm64/kvm/hyp/switch.c | 39
+++++++++++++++++++++++++++++++++++++--
virt/kvm/arm/arm.c | 2 --
4 files changed, 37 insertions(+), 39 deletions(-)
Hi Marc,
This is a preparatory patch for the arm64 entry rework I'm doing: I
need to
move the DAIF manipulation into the same function so that I can replace
that
with a common DAIF+PMR save/restore sequence.
If it's possible to queue this patch for v5.6-rc*, it would help to
minimize
conflict in the v5.7 merge window, and would be much appreciated.
I've tested this on a ThunderX2 machine atop v5.6-rc1 defconfig,
booting the
host and running a test VM.
Thanks,
Mark.
diff --git a/arch/arm/include/asm/kvm_host.h
b/arch/arm/include/asm/kvm_host.h
index c3314b286a61..a827b4d60d38 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -392,9 +392,6 @@ static inline void kvm_arch_vcpu_put_fp(struct
kvm_vcpu *vcpu) {}
static inline void kvm_vcpu_pmu_restore_guest(struct kvm_vcpu *vcpu)
{}
static inline void kvm_vcpu_pmu_restore_host(struct kvm_vcpu *vcpu) {}
-static inline void kvm_arm_vhe_guest_enter(void) {}
-static inline void kvm_arm_vhe_guest_exit(void) {}
-
#define KVM_BP_HARDEN_UNKNOWN -1
#define KVM_BP_HARDEN_WA_NEEDED 0
#define KVM_BP_HARDEN_NOT_REQUIRED 1
diff --git a/arch/arm64/include/asm/kvm_host.h
b/arch/arm64/include/asm/kvm_host.h
index d87aa609d2b6..57fd46acd058 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -626,38 +626,6 @@ static inline void kvm_set_pmu_events(u32 set,
struct perf_event_attr *attr) {}
static inline void kvm_clr_pmu_events(u32 clr) {}
#endif
-static inline void kvm_arm_vhe_guest_enter(void)
-{
- local_daif_mask();
-
- /*
- * Having IRQs masked via PMR when entering the guest means the GIC
- * will not signal the CPU of interrupts of lower priority, and the
- * only way to get out will be via guest exceptions.
- * Naturally, we want to avoid this.
- *
- * local_daif_mask() already sets GIC_PRIO_PSR_I_SET, we just need a
- * dsb to ensure the redistributor is forwards EL2 IRQs to the CPU.
- */
- pmr_sync();
-}
-
-static inline void kvm_arm_vhe_guest_exit(void)
-{
- /*
- * local_daif_restore() takes care to properly restore PSTATE.DAIF
- * and the GIC PMR if the host is using IRQ priorities.
- */
- local_daif_restore(DAIF_PROCCTX_NOIRQ);
-
- /*
- * When we exit from the guest we change a number of CPU
configuration
- * parameters, such as traps. Make sure these changes take effect
- * before running the host or additional guests.
- */
- isb();
-}
-
#define KVM_BP_HARDEN_UNKNOWN -1
#define KVM_BP_HARDEN_WA_NEEDED 0
#define KVM_BP_HARDEN_NOT_REQUIRED 1
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index dfe8dd172512..925086b46136 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -625,7 +625,7 @@ static void __hyp_text __pmu_switch_to_host(struct
kvm_cpu_context *host_ctxt)
}
/* Switch to the guest for VHE systems running in EL2 */
-int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
+static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
{
struct kvm_cpu_context *host_ctxt;
struct kvm_cpu_context *guest_ctxt;
@@ -678,7 +678,42 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
return exit_code;
}
-NOKPROBE_SYMBOL(kvm_vcpu_run_vhe);
+NOKPROBE_SYMBOL(__kvm_vcpu_run_vhe);
+
+int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
+{
+ int ret;
+
+ local_daif_mask();
+
+ /*
+ * Having IRQs masked via PMR when entering the guest means the GIC
+ * will not signal the CPU of interrupts of lower priority, and the
+ * only way to get out will be via guest exceptions.
+ * Naturally, we want to avoid this.
+ *
+ * local_daif_mask() already sets GIC_PRIO_PSR_I_SET, we just need a
+ * dsb to ensure the redistributor is forwards EL2 IRQs to the CPU.
+ */
+ pmr_sync();
+
+ ret = __kvm_vcpu_run_vhe(vcpu);
+
+ /*
+ * local_daif_restore() takes care to properly restore PSTATE.DAIF
+ * and the GIC PMR if the host is using IRQ priorities.
+ */
+ local_daif_restore(DAIF_PROCCTX_NOIRQ);
+
+ /*
+ * When we exit from the guest we change a number of CPU
configuration
+ * parameters, such as traps. Make sure these changes take effect
+ * before running the host or additional guests.
+ */
+ isb();
+
+ return ret;
+}
/* Switch to the guest for legacy non-VHE systems */
int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu)
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index d65a0faa46d8..eda7b624eab8 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -742,9 +742,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu,
struct kvm_run *run)
guest_enter_irqoff();
if (has_vhe()) {
- kvm_arm_vhe_guest_enter();
ret = kvm_vcpu_run_vhe(vcpu);
- kvm_arm_vhe_guest_exit();
} else {
ret = kvm_call_hyp_ret(__kvm_vcpu_run_nvhe, vcpu);
}
Looks good to me, I've taken it as part of the (very small) set of fixes
queued for -rc3.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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