[PATCH 32/37] KVM: arm/arm64: Handle VGICv2 save/restore from the main VGIC code
Christoffer Dall
christoffer.dall at linaro.org
Thu Oct 12 03:41:36 PDT 2017
We can program the GICv2 hypervisor control interface logic directly
from the core vgic code and can instead do the save/restore directly
from the flush/sync functions, which can lead to a number of future
optimizations.
Signed-off-by: Christoffer Dall <christoffer.dall at linaro.org>
---
arch/arm/kvm/hyp/switch.c | 4 --
arch/arm64/include/asm/kvm_hyp.h | 2 -
arch/arm64/kvm/hyp/switch.c | 4 --
virt/kvm/arm/hyp/vgic-v2-sr.c | 83 ------------------------------------
virt/kvm/arm/vgic/vgic-init.c | 22 ++++++----
virt/kvm/arm/vgic/vgic-v2.c | 92 ++++++++++++++++++++++++++++++++++++++++
virt/kvm/arm/vgic/vgic.c | 21 ++++++++-
virt/kvm/arm/vgic/vgic.h | 5 +++
8 files changed, 130 insertions(+), 103 deletions(-)
diff --git a/arch/arm/kvm/hyp/switch.c b/arch/arm/kvm/hyp/switch.c
index c3b9799..0d834f8 100644
--- a/arch/arm/kvm/hyp/switch.c
+++ b/arch/arm/kvm/hyp/switch.c
@@ -91,16 +91,12 @@ static void __hyp_text __vgic_save_state(struct kvm_vcpu *vcpu)
{
if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
__vgic_v3_save_state(vcpu);
- else
- __vgic_v2_save_state(vcpu);
}
static void __hyp_text __vgic_restore_state(struct kvm_vcpu *vcpu)
{
if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
__vgic_v3_restore_state(vcpu);
- else
- __vgic_v2_restore_state(vcpu);
}
static bool __hyp_text __populate_fault_info(struct kvm_vcpu *vcpu)
diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index 28d5f3c..bd3fe64 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -121,8 +121,6 @@ typeof(orig) * __hyp_text fname(void) \
return val; \
}
-void __vgic_v2_save_state(struct kvm_vcpu *vcpu);
-void __vgic_v2_restore_state(struct kvm_vcpu *vcpu);
int __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu);
void __vgic_v3_save_state(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 5692aa0..90da506 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -186,16 +186,12 @@ static void __hyp_text __vgic_save_state(struct kvm_vcpu *vcpu)
{
if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
__vgic_v3_save_state(vcpu);
- else
- __vgic_v2_save_state(vcpu);
}
static void __hyp_text __vgic_restore_state(struct kvm_vcpu *vcpu)
{
if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
__vgic_v3_restore_state(vcpu);
- else
- __vgic_v2_restore_state(vcpu);
}
static bool __hyp_text __true_value(void)
diff --git a/virt/kvm/arm/hyp/vgic-v2-sr.c b/virt/kvm/arm/hyp/vgic-v2-sr.c
index a3f18d3..b433257 100644
--- a/virt/kvm/arm/hyp/vgic-v2-sr.c
+++ b/virt/kvm/arm/hyp/vgic-v2-sr.c
@@ -22,89 +22,6 @@
#include <asm/kvm_emulate.h>
#include <asm/kvm_hyp.h>
-static void __hyp_text save_elrsr(struct kvm_vcpu *vcpu, void __iomem *base)
-{
- struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
- int nr_lr = (kern_hyp_va(&kvm_vgic_global_state))->nr_lr;
- u32 elrsr0, elrsr1;
-
- elrsr0 = readl_relaxed(base + GICH_ELRSR0);
- if (unlikely(nr_lr > 32))
- elrsr1 = readl_relaxed(base + GICH_ELRSR1);
- else
- elrsr1 = 0;
-
-#ifdef CONFIG_CPU_BIG_ENDIAN
- cpu_if->vgic_elrsr = ((u64)elrsr0 << 32) | elrsr1;
-#else
- cpu_if->vgic_elrsr = ((u64)elrsr1 << 32) | elrsr0;
-#endif
-}
-
-static void __hyp_text save_lrs(struct kvm_vcpu *vcpu, void __iomem *base)
-{
- struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
- int i;
- u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
-
- for (i = 0; i < used_lrs; i++) {
- if (cpu_if->vgic_elrsr & (1UL << i))
- cpu_if->vgic_lr[i] &= ~GICH_LR_STATE;
- else
- cpu_if->vgic_lr[i] = readl_relaxed(base + GICH_LR0 + (i * 4));
-
- writel_relaxed(0, base + GICH_LR0 + (i * 4));
- }
-}
-
-/* vcpu is already in the HYP VA space */
-void __hyp_text __vgic_v2_save_state(struct kvm_vcpu *vcpu)
-{
- struct kvm *kvm = kern_hyp_va(vcpu->kvm);
- struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
- struct vgic_dist *vgic = &kvm->arch.vgic;
- void __iomem *base = kern_hyp_va(vgic->vctrl_base);
- u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
-
- if (!base)
- return;
-
- if (used_lrs) {
- cpu_if->vgic_apr = readl_relaxed(base + GICH_APR);
-
- save_elrsr(vcpu, base);
- save_lrs(vcpu, base);
-
- writel_relaxed(0, base + GICH_HCR);
- } else {
- cpu_if->vgic_elrsr = ~0UL;
- cpu_if->vgic_apr = 0;
- }
-}
-
-/* vcpu is already in the HYP VA space */
-void __hyp_text __vgic_v2_restore_state(struct kvm_vcpu *vcpu)
-{
- struct kvm *kvm = kern_hyp_va(vcpu->kvm);
- struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
- struct vgic_dist *vgic = &kvm->arch.vgic;
- void __iomem *base = kern_hyp_va(vgic->vctrl_base);
- int i;
- u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
-
- if (!base)
- return;
-
- if (used_lrs) {
- writel_relaxed(cpu_if->vgic_hcr, base + GICH_HCR);
- writel_relaxed(cpu_if->vgic_apr, base + GICH_APR);
- for (i = 0; i < used_lrs; i++) {
- writel_relaxed(cpu_if->vgic_lr[i],
- base + GICH_LR0 + (i * 4));
- }
- }
-}
-
#ifdef CONFIG_ARM64
/*
* __vgic_v2_perform_cpuif_access -- perform a GICV access on behalf of the
diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
index 5801261f..fa2b565 100644
--- a/virt/kvm/arm/vgic/vgic-init.c
+++ b/virt/kvm/arm/vgic/vgic-init.c
@@ -425,14 +425,16 @@ static int vgic_init_cpu_dying(unsigned int cpu)
return 0;
}
-static irqreturn_t vgic_maintenance_handler(int irq, void *data)
+static irqreturn_t vgic_v3_maintenance_handler(int irq, void *data)
{
- /*
- * We cannot rely on the vgic maintenance interrupt to be
- * delivered synchronously. This means we can only use it to
- * exit the VM, and we perform the handling of EOIed
- * interrupts on the exit path (see vgic_process_maintenance).
- */
+ BUG(); /* Not implemented lazy save/restore on GICv3 */
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t vgic_v2_maintenance_handler(int irq, void *data)
+{
+ struct kvm_vcpu *vcpu = (struct kvm_vcpu *)data;
+ vgic_v2_handle_maintenance(vcpu);
return IRQ_HANDLED;
}
@@ -464,6 +466,7 @@ void kvm_vgic_init_cpu_hardware(void)
int kvm_vgic_hyp_init(void)
{
const struct gic_kvm_info *gic_kvm_info;
+ irqreturn_t (*handler)(int irq, void *data);
int ret;
gic_kvm_info = gic_get_kvm_info();
@@ -478,6 +481,7 @@ int kvm_vgic_hyp_init(void)
switch (gic_kvm_info->type) {
case GIC_V2:
ret = vgic_v2_probe(gic_kvm_info);
+ handler = vgic_v2_maintenance_handler;
break;
case GIC_V3:
ret = vgic_v3_probe(gic_kvm_info);
@@ -485,6 +489,7 @@ int kvm_vgic_hyp_init(void)
static_branch_enable(&kvm_vgic_global_state.gicv3_cpuif);
kvm_info("GIC system register CPU interface enabled\n");
}
+ handler = vgic_v3_maintenance_handler;
break;
default:
ret = -ENODEV;
@@ -494,8 +499,7 @@ int kvm_vgic_hyp_init(void)
return ret;
kvm_vgic_global_state.maint_irq = gic_kvm_info->maint_irq;
- ret = request_percpu_irq(kvm_vgic_global_state.maint_irq,
- vgic_maintenance_handler,
+ ret = request_percpu_irq(kvm_vgic_global_state.maint_irq, handler,
"vgic", kvm_get_running_vcpus());
if (ret) {
kvm_err("Cannot register interrupt %d\n",
diff --git a/virt/kvm/arm/vgic/vgic-v2.c b/virt/kvm/arm/vgic/vgic-v2.c
index 8089710..259079b 100644
--- a/virt/kvm/arm/vgic/vgic-v2.c
+++ b/virt/kvm/arm/vgic/vgic-v2.c
@@ -37,6 +37,17 @@ void vgic_v2_init_lrs(void)
vgic_v2_write_lr(i, 0);
}
+void vgic_v2_handle_maintenance(struct kvm_vcpu *vcpu)
+{
+ void __iomem *base = kvm_vgic_global_state.vctrl_base;
+
+ /*
+ * Disable maintenance interrupt as we only use it to generate an exit
+ * from the VM.
+ */
+ writel_relaxed(0, base + GICH_HCR);
+}
+
void vgic_v2_set_underflow(struct kvm_vcpu *vcpu)
{
struct vgic_v2_cpu_if *cpuif = &vcpu->arch.vgic_cpu.vgic_v2;
@@ -393,6 +404,87 @@ int vgic_v2_probe(const struct gic_kvm_info *info)
return ret;
}
+static void save_elrsr(struct kvm_vcpu *vcpu, void __iomem *base)
+{
+ struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
+ int nr_lr = kvm_vgic_global_state.nr_lr;
+ u32 elrsr0, elrsr1;
+
+ elrsr0 = readl_relaxed(base + GICH_ELRSR0);
+ if (unlikely(nr_lr > 32))
+ elrsr1 = readl_relaxed(base + GICH_ELRSR1);
+ else
+ elrsr1 = 0;
+
+#ifdef CONFIG_CPU_BIG_ENDIAN
+ cpu_if->vgic_elrsr = ((u64)elrsr0 << 32) | elrsr1;
+#else
+ cpu_if->vgic_elrsr = ((u64)elrsr1 << 32) | elrsr0;
+#endif
+}
+
+static void save_lrs(struct kvm_vcpu *vcpu, void __iomem *base)
+{
+ struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
+ int i;
+ u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+
+ for (i = 0; i < used_lrs; i++) {
+ if (cpu_if->vgic_elrsr & (1UL << i))
+ cpu_if->vgic_lr[i] &= ~GICH_LR_STATE;
+ else
+ cpu_if->vgic_lr[i] = readl_relaxed(base + GICH_LR0 + (i * 4));
+
+ writel_relaxed(0, base + GICH_LR0 + (i * 4));
+ }
+}
+
+void vgic_v2_save_state(struct kvm_vcpu *vcpu)
+{
+ struct kvm *kvm = vcpu->kvm;
+ struct vgic_dist *vgic = &kvm->arch.vgic;
+ struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
+ void __iomem *base = vgic->vctrl_base;
+ u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+
+ if (!base)
+ return;
+
+ if (used_lrs) {
+ cpu_if->vgic_apr = readl_relaxed(base + GICH_APR);
+
+ save_elrsr(vcpu, base);
+ save_lrs(vcpu, base);
+
+ writel_relaxed(0, base + GICH_HCR);
+ } else {
+ cpu_if->vgic_elrsr = ~0UL;
+ cpu_if->vgic_apr = 0;
+ }
+}
+
+void vgic_v2_restore_state(struct kvm_vcpu *vcpu)
+{
+ struct kvm *kvm = vcpu->kvm;
+ struct vgic_dist *vgic = &kvm->arch.vgic;
+ struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
+ void __iomem *base = vgic->vctrl_base;
+ u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+ int i;
+
+ if (!base)
+ return;
+
+ if (used_lrs) {
+ writel_relaxed(cpu_if->vgic_hcr, base + GICH_HCR);
+ writel_relaxed(cpu_if->vgic_apr, base + GICH_APR);
+ for (i = 0; i < used_lrs; i++) {
+ writel_relaxed(cpu_if->vgic_lr[i],
+ base + GICH_LR0 + (i * 4));
+ }
+ }
+}
+
void vgic_v2_load(struct kvm_vcpu *vcpu)
{
struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
index b1bd238..790fd66 100644
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -18,6 +18,8 @@
#include <linux/kvm_host.h>
#include <linux/list_sort.h>
+#include <asm/kvm_hyp.h>
+
#include "vgic.h"
#define CREATE_TRACE_POINTS
@@ -683,11 +685,19 @@ static void vgic_flush_lr_state(struct kvm_vcpu *vcpu)
vgic_clear_lr(vcpu, count);
}
+static inline void vgic_save_state(struct kvm_vcpu *vcpu)
+{
+ if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+ vgic_v2_save_state(vcpu);
+}
+
/* Sync back the hardware VGIC state into our emulation after a guest's run. */
void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
{
struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+ vgic_save_state(vcpu);
+
/* An empty ap_list_head implies used_lrs == 0 */
if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head))
return;
@@ -697,6 +707,12 @@ void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
vgic_prune_ap_list(vcpu);
}
+static inline void vgic_restore_state(struct kvm_vcpu *vcpu)
+{
+ if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+ vgic_v2_restore_state(vcpu);
+}
+
/* Flush our emulation state into the GIC hardware before entering the guest. */
void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
{
@@ -710,13 +726,16 @@ void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
* this.
*/
if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head))
- return;
+ goto out;
DEBUG_SPINLOCK_BUG_ON(!irqs_disabled());
spin_lock(&vcpu->arch.vgic_cpu.ap_list_lock);
vgic_flush_lr_state(vcpu);
spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock);
+
+out:
+ vgic_restore_state(vcpu);
}
void kvm_vgic_load(struct kvm_vcpu *vcpu)
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 4f8aecb..9895396 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -167,6 +167,11 @@ int vgic_register_dist_iodev(struct kvm *kvm, gpa_t dist_base_address,
void vgic_v2_init_lrs(void);
void vgic_v2_load(struct kvm_vcpu *vcpu);
void vgic_v2_put(struct kvm_vcpu *vcpu);
+void vgic_v2_handle_maintenance(struct kvm_vcpu *vcpu);
+
+void vgic_v2_save_state(struct kvm_vcpu *vcpu);
+void vgic_v2_restore_state(struct kvm_vcpu *vcpu);
+
static inline void vgic_get_irq_kref(struct vgic_irq *irq)
{
--
2.9.0
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