diff mbox series

[09/26] KVM: arm64: vgic-v3: Take cpu_if pointer directly instead of vcpu

Message ID 20200422120050.3693593-10-maz@kernel.org (mailing list archive)
State New, archived
Headers show
Series KVM: arm64: Preliminary NV patches | expand

Commit Message

Marc Zyngier April 22, 2020, noon UTC 
From: Christoffer Dall <christoffer.dall@arm.com>

If we move the used_lrs field to the version-specific cpu interface
structure, the following functions only operate on the struct
vgic_v3_cpu_if and not the full vcpu:

  __vgic_v3_save_state
  __vgic_v3_restore_state
  __vgic_v3_activate_traps
  __vgic_v3_deactivate_traps
  __vgic_v3_save_aprs
  __vgic_v3_restore_aprs

This is going to be very useful for nested virt, so move the used_lrs
field and change the prototypes and implementations of these functions to
take the cpu_if parameter directly.

No functional change.

Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/include/asm/kvm_hyp.h | 12 ++++++------
 arch/arm64/kvm/hyp/switch.c      |  8 ++++----
 include/kvm/arm_vgic.h           |  5 ++++-
 virt/kvm/arm/hyp/vgic-v3-sr.c    | 33 ++++++++++----------------------
 virt/kvm/arm/vgic/vgic-v2.c      | 10 +++++-----
 virt/kvm/arm/vgic/vgic-v3.c      | 14 ++++++++------
 virt/kvm/arm/vgic/vgic.c         | 25 ++++++++++++++++--------
 7 files changed, 54 insertions(+), 53 deletions(-)

Comments

James Morse May 7, 2020, 4:26 p.m. UTC | #1 
Hi Marc, Christoffer,

On 22/04/2020 13:00, Marc Zyngier wrote:
> From: Christoffer Dall <christoffer.dall@arm.com>
> 
> If we move the used_lrs field to the version-specific cpu interface
> structure, the following functions only operate on the struct
> vgic_v3_cpu_if and not the full vcpu:
> 
>   __vgic_v3_save_state
>   __vgic_v3_restore_state
>   __vgic_v3_activate_traps
>   __vgic_v3_deactivate_traps
>   __vgic_v3_save_aprs
>   __vgic_v3_restore_aprs
> 
> This is going to be very useful for nested virt, 

... because you don't need to consider whether the vcpu is running in vEL2?


> so move the used_lrs
> field and change the prototypes and implementations of these functions to
> take the cpu_if parameter directly.


> No functional change.

Looks like no change!

Reviewed-by: James Morse <james.morse@arm.com>


Thanks,

James
Marc Zyngier May 8, 2020, 12:20 p.m. UTC | #2 
On Thu, 7 May 2020 17:26:06 +0100
James Morse <james.morse@arm.com> wrote:

Hi James,

> Hi Marc, Christoffer,
> 
> On 22/04/2020 13:00, Marc Zyngier wrote:
> > From: Christoffer Dall <christoffer.dall@arm.com>
> > 
> > If we move the used_lrs field to the version-specific cpu interface
> > structure, the following functions only operate on the struct
> > vgic_v3_cpu_if and not the full vcpu:
> > 
> >   __vgic_v3_save_state
> >   __vgic_v3_restore_state
> >   __vgic_v3_activate_traps
> >   __vgic_v3_deactivate_traps
> >   __vgic_v3_save_aprs
> >   __vgic_v3_restore_aprs
> > 
> > This is going to be very useful for nested virt,   
> 
> ... because you don't need to consider whether the vcpu is running in vEL2?

That's one of the reasons, as vEL2 is still EL1.

But things become really fun when you run a L2 guest, which is an EL1
guest from the PoV of the guest hypervisor (aka L1). At this stage
what you feed to the HW is not the state that could be populated by L0
for L1, but instead what L1 has created for L2 (with a bit of
additional repainting to adjust some of the interrupt numbers).

So we build a shadow cpu_if on the fly and pass it to the normal vgic
handling functions. I told you it was fun! ;-)

> > so move the used_lrs
> > field and change the prototypes and implementations of these functions to
> > take the cpu_if parameter directly.  
> 
> 
> > No functional change.  
> 
> Looks like no change!
> 
> Reviewed-by: James Morse <james.morse@arm.com>

Thanks!

	M.
diff mbox series

Patch

diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index dcb63bf941057..f3c3d7645000f 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -55,12 +55,12 @@ 
 
 int __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu);
 
-void __vgic_v3_save_state(struct kvm_vcpu *vcpu);
-void __vgic_v3_restore_state(struct kvm_vcpu *vcpu);
-void __vgic_v3_activate_traps(struct kvm_vcpu *vcpu);
-void __vgic_v3_deactivate_traps(struct kvm_vcpu *vcpu);
-void __vgic_v3_save_aprs(struct kvm_vcpu *vcpu);
-void __vgic_v3_restore_aprs(struct kvm_vcpu *vcpu);
+void __vgic_v3_save_state(struct vgic_v3_cpu_if *cpu_if);
+void __vgic_v3_restore_state(struct vgic_v3_cpu_if *cpu_if);
+void __vgic_v3_activate_traps(struct vgic_v3_cpu_if *cpu_if);
+void __vgic_v3_deactivate_traps(struct vgic_v3_cpu_if *cpu_if);
+void __vgic_v3_save_aprs(struct vgic_v3_cpu_if *cpu_if);
+void __vgic_v3_restore_aprs(struct vgic_v3_cpu_if *cpu_if);
 int __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu);
 
 void __timer_enable_traps(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index d79319038b119..c48c96565f1a7 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -270,8 +270,8 @@  static void __hyp_text __deactivate_vm(struct kvm_vcpu *vcpu)
 static void __hyp_text __hyp_vgic_save_state(struct kvm_vcpu *vcpu)
 {
 	if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) {
-		__vgic_v3_save_state(vcpu);
-		__vgic_v3_deactivate_traps(vcpu);
+		__vgic_v3_save_state(&vcpu->arch.vgic_cpu.vgic_v3);
+		__vgic_v3_deactivate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
 	}
 }
 
@@ -279,8 +279,8 @@  static void __hyp_text __hyp_vgic_save_state(struct kvm_vcpu *vcpu)
 static void __hyp_text __hyp_vgic_restore_state(struct kvm_vcpu *vcpu)
 {
 	if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) {
-		__vgic_v3_activate_traps(vcpu);
-		__vgic_v3_restore_state(vcpu);
+		__vgic_v3_activate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
+		__vgic_v3_restore_state(&vcpu->arch.vgic_cpu.vgic_v3);
 	}
 }
 
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 69f4164d64776..a8d8fdcd37230 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -274,6 +274,8 @@  struct vgic_v2_cpu_if {
 	u32		vgic_vmcr;
 	u32		vgic_apr;
 	u32		vgic_lr[VGIC_V2_MAX_LRS];
+
+	unsigned int used_lrs;
 };
 
 struct vgic_v3_cpu_if {
@@ -291,6 +293,8 @@  struct vgic_v3_cpu_if {
 	 * linking the Linux IRQ subsystem and the ITS together.
 	 */
 	struct its_vpe	its_vpe;
+
+	unsigned int used_lrs;
 };
 
 struct vgic_cpu {
@@ -300,7 +304,6 @@  struct vgic_cpu {
 		struct vgic_v3_cpu_if	vgic_v3;
 	};
 
-	unsigned int used_lrs;
 	struct vgic_irq private_irqs[VGIC_NR_PRIVATE_IRQS];
 
 	raw_spinlock_t ap_list_lock;	/* Protects the ap_list */
diff --git a/virt/kvm/arm/hyp/vgic-v3-sr.c b/virt/kvm/arm/hyp/vgic-v3-sr.c
index ccf1fde9836c1..2ea9a0b73fc44 100644
--- a/virt/kvm/arm/hyp/vgic-v3-sr.c
+++ b/virt/kvm/arm/hyp/vgic-v3-sr.c
@@ -194,10 +194,9 @@  static u32 __hyp_text __vgic_v3_read_ap1rn(int n)
 	return val;
 }
 
-void __hyp_text __vgic_v3_save_state(struct kvm_vcpu *vcpu)
+void __hyp_text __vgic_v3_save_state(struct vgic_v3_cpu_if *cpu_if)
 {
-	struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
-	u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+	u64 used_lrs = cpu_if->used_lrs;
 
 	/*
 	 * Make sure stores to the GIC via the memory mapped interface
@@ -230,10 +229,9 @@  void __hyp_text __vgic_v3_save_state(struct kvm_vcpu *vcpu)
 	}
 }
 
-void __hyp_text __vgic_v3_restore_state(struct kvm_vcpu *vcpu)
+void __hyp_text __vgic_v3_restore_state(struct vgic_v3_cpu_if *cpu_if)
 {
-	struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
-	u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+	u64 used_lrs = cpu_if->used_lrs;
 	int i;
 
 	if (used_lrs || cpu_if->its_vpe.its_vm) {
@@ -257,10 +255,8 @@  void __hyp_text __vgic_v3_restore_state(struct kvm_vcpu *vcpu)
 	}
 }
 
-void __hyp_text __vgic_v3_activate_traps(struct kvm_vcpu *vcpu)
+void __hyp_text __vgic_v3_activate_traps(struct vgic_v3_cpu_if *cpu_if)
 {
-	struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
-
 	/*
 	 * VFIQEn is RES1 if ICC_SRE_EL1.SRE is 1. This causes a
 	 * Group0 interrupt (as generated in GICv2 mode) to be
@@ -306,9 +302,8 @@  void __hyp_text __vgic_v3_activate_traps(struct kvm_vcpu *vcpu)
 		write_gicreg(cpu_if->vgic_hcr, ICH_HCR_EL2);
 }
 
-void __hyp_text __vgic_v3_deactivate_traps(struct kvm_vcpu *vcpu)
+void __hyp_text __vgic_v3_deactivate_traps(struct vgic_v3_cpu_if *cpu_if)
 {
-	struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
 	u64 val;
 
 	if (!cpu_if->vgic_sre) {
@@ -333,15 +328,11 @@  void __hyp_text __vgic_v3_deactivate_traps(struct kvm_vcpu *vcpu)
 		write_gicreg(0, ICH_HCR_EL2);
 }
 
-void __hyp_text __vgic_v3_save_aprs(struct kvm_vcpu *vcpu)
+void __hyp_text __vgic_v3_save_aprs(struct vgic_v3_cpu_if *cpu_if)
 {
-	struct vgic_v3_cpu_if *cpu_if;
 	u64 val;
 	u32 nr_pre_bits;
 
-	vcpu = kern_hyp_va(vcpu);
-	cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
-
 	val = read_gicreg(ICH_VTR_EL2);
 	nr_pre_bits = vtr_to_nr_pre_bits(val);
 
@@ -370,15 +361,11 @@  void __hyp_text __vgic_v3_save_aprs(struct kvm_vcpu *vcpu)
 	}
 }
 
-void __hyp_text __vgic_v3_restore_aprs(struct kvm_vcpu *vcpu)
+void __hyp_text __vgic_v3_restore_aprs(struct vgic_v3_cpu_if *cpu_if)
 {
-	struct vgic_v3_cpu_if *cpu_if;
 	u64 val;
 	u32 nr_pre_bits;
 
-	vcpu = kern_hyp_va(vcpu);
-	cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
-
 	val = read_gicreg(ICH_VTR_EL2);
 	nr_pre_bits = vtr_to_nr_pre_bits(val);
 
@@ -453,7 +440,7 @@  static int __hyp_text __vgic_v3_highest_priority_lr(struct kvm_vcpu *vcpu,
 						    u32 vmcr,
 						    u64 *lr_val)
 {
-	unsigned int used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+	unsigned int used_lrs = vcpu->arch.vgic_cpu.vgic_v3.used_lrs;
 	u8 priority = GICv3_IDLE_PRIORITY;
 	int i, lr = -1;
 
@@ -492,7 +479,7 @@  static int __hyp_text __vgic_v3_highest_priority_lr(struct kvm_vcpu *vcpu,
 static int __hyp_text __vgic_v3_find_active_lr(struct kvm_vcpu *vcpu,
 					       int intid, u64 *lr_val)
 {
-	unsigned int used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+	unsigned int used_lrs = vcpu->arch.vgic_cpu.vgic_v3.used_lrs;
 	int i;
 
 	for (i = 0; i < used_lrs; i++) {
diff --git a/virt/kvm/arm/vgic/vgic-v2.c b/virt/kvm/arm/vgic/vgic-v2.c
index 621cc168fe3f7..ebf53a4e12963 100644
--- a/virt/kvm/arm/vgic/vgic-v2.c
+++ b/virt/kvm/arm/vgic/vgic-v2.c
@@ -56,7 +56,7 @@  void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu)
 
 	cpuif->vgic_hcr &= ~GICH_HCR_UIE;
 
-	for (lr = 0; lr < vgic_cpu->used_lrs; lr++) {
+	for (lr = 0; lr < vgic_cpu->vgic_v2.used_lrs; lr++) {
 		u32 val = cpuif->vgic_lr[lr];
 		u32 cpuid, intid = val & GICH_LR_VIRTUALID;
 		struct vgic_irq *irq;
@@ -120,7 +120,7 @@  void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu)
 		vgic_put_irq(vcpu->kvm, irq);
 	}
 
-	vgic_cpu->used_lrs = 0;
+	cpuif->used_lrs = 0;
 }
 
 /*
@@ -427,7 +427,7 @@  int vgic_v2_probe(const struct gic_kvm_info *info)
 static void save_lrs(struct kvm_vcpu *vcpu, void __iomem *base)
 {
 	struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
-	u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+	u64 used_lrs = cpu_if->used_lrs;
 	u64 elrsr;
 	int i;
 
@@ -448,7 +448,7 @@  static void save_lrs(struct kvm_vcpu *vcpu, void __iomem *base)
 void vgic_v2_save_state(struct kvm_vcpu *vcpu)
 {
 	void __iomem *base = kvm_vgic_global_state.vctrl_base;
-	u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+	u64 used_lrs = vcpu->arch.vgic_cpu.vgic_v2.used_lrs;
 
 	if (!base)
 		return;
@@ -463,7 +463,7 @@  void vgic_v2_restore_state(struct kvm_vcpu *vcpu)
 {
 	struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
 	void __iomem *base = kvm_vgic_global_state.vctrl_base;
-	u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+	u64 used_lrs = cpu_if->used_lrs;
 	int i;
 
 	if (!base)
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index 2c9fc13e2c590..118d044f48ddf 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -39,7 +39,7 @@  void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu)
 
 	cpuif->vgic_hcr &= ~ICH_HCR_UIE;
 
-	for (lr = 0; lr < vgic_cpu->used_lrs; lr++) {
+	for (lr = 0; lr < cpuif->used_lrs; lr++) {
 		u64 val = cpuif->vgic_lr[lr];
 		u32 intid, cpuid;
 		struct vgic_irq *irq;
@@ -111,7 +111,7 @@  void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu)
 		vgic_put_irq(vcpu->kvm, irq);
 	}
 
-	vgic_cpu->used_lrs = 0;
+	cpuif->used_lrs = 0;
 }
 
 /* Requires the irq to be locked already */
@@ -664,10 +664,10 @@  void vgic_v3_load(struct kvm_vcpu *vcpu)
 	if (likely(cpu_if->vgic_sre))
 		kvm_call_hyp(__vgic_v3_write_vmcr, cpu_if->vgic_vmcr);
 
-	kvm_call_hyp(__vgic_v3_restore_aprs, vcpu);
+	kvm_call_hyp(__vgic_v3_restore_aprs, kern_hyp_va(cpu_if));
 
 	if (has_vhe())
-		__vgic_v3_activate_traps(vcpu);
+		__vgic_v3_activate_traps(cpu_if);
 
 	WARN_ON(vgic_v4_load(vcpu));
 }
@@ -682,12 +682,14 @@  void vgic_v3_vmcr_sync(struct kvm_vcpu *vcpu)
 
 void vgic_v3_put(struct kvm_vcpu *vcpu)
 {
+	struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
+
 	WARN_ON(vgic_v4_put(vcpu, false));
 
 	vgic_v3_vmcr_sync(vcpu);
 
-	kvm_call_hyp(__vgic_v3_save_aprs, vcpu);
+	kvm_call_hyp(__vgic_v3_save_aprs, kern_hyp_va(cpu_if));
 
 	if (has_vhe())
-		__vgic_v3_deactivate_traps(vcpu);
+		__vgic_v3_deactivate_traps(cpu_if);
 }
diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
index 99b02ca730a87..c3643b7f101b7 100644
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -786,6 +786,7 @@  static void vgic_flush_lr_state(struct kvm_vcpu *vcpu)
 	int count;
 	bool multi_sgi;
 	u8 prio = 0xff;
+	int i = 0;
 
 	lockdep_assert_held(&vgic_cpu->ap_list_lock);
 
@@ -827,11 +828,14 @@  static void vgic_flush_lr_state(struct kvm_vcpu *vcpu)
 		}
 	}
 
-	vcpu->arch.vgic_cpu.used_lrs = count;
-
 	/* Nuke remaining LRs */
-	for ( ; count < kvm_vgic_global_state.nr_lr; count++)
-		vgic_clear_lr(vcpu, count);
+	for (i = count ; i < kvm_vgic_global_state.nr_lr; i++)
+		vgic_clear_lr(vcpu, i);
+
+	if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+		vcpu->arch.vgic_cpu.vgic_v2.used_lrs = count;
+	else
+		vcpu->arch.vgic_cpu.vgic_v3.used_lrs = count;
 }
 
 static inline bool can_access_vgic_from_kernel(void)
@@ -849,13 +853,13 @@  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);
 	else
-		__vgic_v3_save_state(vcpu);
+		__vgic_v3_save_state(&vcpu->arch.vgic_cpu.vgic_v3);
 }
 
 /* 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;
+	int used_lrs;
 
 	/* An empty ap_list_head implies used_lrs == 0 */
 	if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head))
@@ -864,7 +868,12 @@  void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
 	if (can_access_vgic_from_kernel())
 		vgic_save_state(vcpu);
 
-	if (vgic_cpu->used_lrs)
+	if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+		used_lrs = vcpu->arch.vgic_cpu.vgic_v2.used_lrs;
+	else
+		used_lrs = vcpu->arch.vgic_cpu.vgic_v3.used_lrs;
+
+	if (used_lrs)
 		vgic_fold_lr_state(vcpu);
 	vgic_prune_ap_list(vcpu);
 }
@@ -874,7 +883,7 @@  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);
 	else
-		__vgic_v3_restore_state(vcpu);
+		__vgic_v3_restore_state(&vcpu->arch.vgic_cpu.vgic_v3);
 }
 
 /* Flush our emulation state into the GIC hardware before entering the guest. */