diff mbox

[v4,2/5] ARM: KVM: arch_timers: Add minimal infrastructure

Message ID 20121110154611.3274.87138.stgit@chazy-air (mailing list archive)
State New, archived
Headers show

Commit Message

Christoffer Dall Nov. 10, 2012, 3:46 p.m. UTC 
From: Marc Zyngier <marc.zyngier@arm.com>

Add some very minimal architected timer related infrastructure.
For the moment, we just provide empty structures, and enable/disable
access to the physical timer across world switch.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
---
 arch/arm/include/asm/kvm_arch_timer.h |   45 +++++++++++++++++++++++++++++++++
 arch/arm/include/asm/kvm_host.h       |    5 ++++
 arch/arm/kvm/interrupts.S             |    2 +
 arch/arm/kvm/interrupts_head.S        |   19 ++++++++++++++
 4 files changed, 71 insertions(+)
 create mode 100644 arch/arm/include/asm/kvm_arch_timer.h

Comments

Will Deacon Nov. 23, 2012, 3:23 p.m. UTC | #1 
On Sat, Nov 10, 2012 at 03:46:12PM +0000, Christoffer Dall wrote:
> From: Marc Zyngier <marc.zyngier@arm.com>
> 
> Add some very minimal architected timer related infrastructure.
> For the moment, we just provide empty structures, and enable/disable
> access to the physical timer across world switch.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>

Is it even worth having this patch? It doesn't seem to do much other than
stub everything out, so I'd be inclined to fold it in with the next one.

Will
Christoffer Dall Nov. 30, 2012, 10:24 p.m. UTC | #2 
On Fri, Nov 23, 2012 at 10:23 AM, Will Deacon <will.deacon@arm.com> wrote:
> On Sat, Nov 10, 2012 at 03:46:12PM +0000, Christoffer Dall wrote:
>> From: Marc Zyngier <marc.zyngier@arm.com>
>>
>> Add some very minimal architected timer related infrastructure.
>> For the moment, we just provide empty structures, and enable/disable
>> access to the physical timer across world switch.
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
>
> Is it even worth having this patch? It doesn't seem to do much other than
> stub everything out, so I'd be inclined to fold it in with the next one.
>
done,
-Christoffer
diff mbox

Patch

diff --git a/arch/arm/include/asm/kvm_arch_timer.h b/arch/arm/include/asm/kvm_arch_timer.h
new file mode 100644
index 0000000..513b852
--- /dev/null
+++ b/arch/arm/include/asm/kvm_arch_timer.h
@@ -0,0 +1,45 @@ 
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef __ASM_ARM_KVM_ARCH_TIMER_H
+#define __ASM_ARM_KVM_ARCH_TIMER_H
+
+struct arch_timer_kvm {
+};
+
+struct arch_timer_cpu {
+};
+
+#ifndef CONFIG_KVM_ARM_TIMER
+static inline int kvm_timer_hyp_init(void)
+{
+	return 0;
+};
+
+static inline int kvm_timer_init(struct kvm *kvm)
+{
+	return 0;
+}
+
+static inline void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu) {}
+static inline void kvm_timer_sync_to_cpu(struct kvm_vcpu *vcpu) {}
+static inline void kvm_timer_sync_from_cpu(struct kvm_vcpu *vcpu) {}
+static inline void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu) {}
+#endif
+
+#endif
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 49ba25a..41012ef 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -24,6 +24,7 @@ 
 #include <asm/fpstate.h>
 #include <asm/kvm_decode.h>
 #include <asm/kvm_vgic.h>
+#include <asm/kvm_arch_timer.h>
 
 #define KVM_MAX_VCPUS CONFIG_KVM_ARM_MAX_VCPUS
 #define KVM_MEMORY_SLOTS 32
@@ -48,6 +49,9 @@  struct kvm_arch {
 	/* VTTBR value associated with below pgd and vmid */
 	u64    vttbr;
 
+	/* Timer */
+	struct arch_timer_kvm	timer;
+
 	/*
 	 * Anything that is not used directly from assembly code goes
 	 * here.
@@ -98,6 +102,7 @@  struct kvm_vcpu_arch {
 
 	/* VGIC state */
 	struct vgic_cpu vgic_cpu;
+	struct arch_timer_cpu timer_cpu;
 
 	/*
 	 * Anything that is not used directly from assembly code goes
diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S
index e418c9b..5a09e89 100644
--- a/arch/arm/kvm/interrupts.S
+++ b/arch/arm/kvm/interrupts.S
@@ -92,6 +92,7 @@  ENTRY(__kvm_vcpu_run)
 	save_host_regs
 
 	restore_vgic_state r0
+	restore_timer_state r0
 
 	@ Store hardware CP15 state and load guest state
 	read_cp15_state
@@ -186,6 +187,7 @@  after_vfp_restore:
 	read_cp15_state 1, r1
 	write_cp15_state
 
+	save_timer_state r1
 	save_vgic_state	r1
 
 	restore_host_regs
diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S
index c2423d8..0003aab 100644
--- a/arch/arm/kvm/interrupts_head.S
+++ b/arch/arm/kvm/interrupts_head.S
@@ -418,6 +418,25 @@ 
 #endif
 .endm
 
+#define CNTHCTL_PL1PCTEN	(1 << 0)
+#define CNTHCTL_PL1PCEN		(1 << 1)
+
+.macro save_timer_state	vcpup
+	@ Allow physical timer/counter access for the host
+	mrc	p15, 4, r2, c14, c1, 0	@ CNTHCTL
+	orr	r2, r2, #(CNTHCTL_PL1PCEN | CNTHCTL_PL1PCTEN)
+	mcr	p15, 4, r2, c14, c1, 0	@ CNTHCTL
+.endm
+
+.macro restore_timer_state vcpup
+	@ Disallow physical timer access for the guest
+	@ Physical counter access is allowed
+	mrc	p15, 4, r2, c14, c1, 0	@ CNTHCTL
+	orr	r2, r2, #CNTHCTL_PL1PCTEN
+	bic	r2, r2, #CNTHCTL_PL1PCEN
+	mcr	p15, 4, r2, c14, c1, 0	@ CNTHCTL
+.endm
+
 /* Configures the HSTR (Hyp System Trap Register) on entry/return
  * (hardware reset value is 0) */
 .macro set_hstr entry