diff mbox

[RFC,v2,1/4] arm/arm64: vgic-new: Introduce 64-bit reg access support

Message ID 1470740326-27751-2-git-send-email-vijay.kilari@gmail.com
State New
Headers show

Commit Message

Vijay Kilari Aug. 9, 2016, 10:58 a.m. UTC
From: Vijaya Kumar K <Vijaya.Kumar@cavium.com>


vgic_attr_regs_access() handles only 32-bit register
value. Pass u64 as parameter and locally handle 32-bit
reads and writes depending on attribute group.

Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com>

---
 virt/kvm/arm/vgic/vgic-kvm-device.c | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

-- 
1.9.1


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Comments

Christoffer Dall Aug. 16, 2016, 3:01 p.m. UTC | #1
On Tue, Aug 09, 2016 at 04:28:43PM +0530, vijay.kilari@gmail.com wrote:
> From: Vijaya Kumar K <Vijaya.Kumar@cavium.com>

> 

> vgic_attr_regs_access() handles only 32-bit register

> value. Pass u64 as parameter and locally handle 32-bit

> reads and writes depending on attribute group.

> 

> Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com>

> ---

>  virt/kvm/arm/vgic/vgic-kvm-device.c | 26 +++++++++++++++++++-------

>  1 file changed, 19 insertions(+), 7 deletions(-)

> 

> diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c

> index 0130c4b..06de322 100644

> --- a/virt/kvm/arm/vgic/vgic-kvm-device.c

> +++ b/virt/kvm/arm/vgic/vgic-kvm-device.c

> @@ -236,12 +236,13 @@ void kvm_register_vgic_device(unsigned long type)

>   */

>  static int vgic_attr_regs_access(struct kvm_device *dev,

>  				 struct kvm_device_attr *attr,

> -				 u32 *reg, bool is_write)

> +				 u64 *reg, bool is_write)

>  {

>  	gpa_t addr;

>  	int cpuid, ret, c;

>  	struct kvm_vcpu *vcpu, *tmp_vcpu;

>  	int vcpu_lock_idx = -1;

> +	u32 tmp32;

>  

>  	cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >>

>  		 KVM_DEV_ARM_VGIC_CPUID_SHIFT;

> @@ -272,12 +273,19 @@ static int vgic_attr_regs_access(struct kvm_device *dev,

>  		vcpu_lock_idx = c;

>  	}

>  

> +	if (is_write)

> +		tmp32 = *reg;

> +


I'm not a fan of this, from seeing that you do the read conversion
inside the case statements I gather you put this here so you only have
to have it once, even though you throw it away if you're doing 64-bit
accesses?

But a greater concern is the vgic_init() call above, which you don't
handle.

I thought we were supposed to get rid of all this lazy vgic init stuff.

Let me send you a patch series of how to rework this vgic_attr function
so that you can reuse some of the functionality and implement a new
gicv3 function on top of that.

Thanks,
-Christoffer

>  	switch (attr->group) {

>  	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:

> -		ret = vgic_v2_cpuif_uaccess(vcpu, is_write, addr, reg);

> +		ret = vgic_v2_cpuif_uaccess(vcpu, is_write, addr, &tmp32);

> +		if (!is_write)

> +			*reg = tmp32;

>  		break;

>  	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:

> -		ret = vgic_v2_dist_uaccess(vcpu, is_write, addr, reg);

> +		ret = vgic_v2_dist_uaccess(vcpu, is_write, addr, &tmp32);

> +		if (!is_write)

> +			*reg = tmp32;



>  		break;

>  	default:

>  		ret = -EINVAL;

> @@ -309,11 +317,13 @@ static int vgic_v2_set_attr(struct kvm_device *dev,

>  	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:

>  	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: {

>  		u32 __user *uaddr = (u32 __user *)(long)attr->addr;

> -		u32 reg;

> +		u32 tmp32;

> +		u64 reg;

>  

> -		if (get_user(reg, uaddr))

> +		if (get_user(tmp32, uaddr))

>  			return -EFAULT;

>  

> +		reg = tmp32;

>  		return vgic_attr_regs_access(dev, attr, &reg, true);

>  	}

>  	}

> @@ -334,12 +344,14 @@ static int vgic_v2_get_attr(struct kvm_device *dev,

>  	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:

>  	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: {

>  		u32 __user *uaddr = (u32 __user *)(long)attr->addr;

> -		u32 reg = 0;

> +		u32 tmp32;

> +		u64 reg;

>  

>  		ret = vgic_attr_regs_access(dev, attr, &reg, false);

>  		if (ret)

>  			return ret;

> -		return put_user(reg, uaddr);

> +		tmp32 = reg;

> +		return put_user(tmp32, uaddr);

>  	}

>  	}

>  

> -- 

> 1.9.1

> 


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diff mbox

Patch

diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c
index 0130c4b..06de322 100644
--- a/virt/kvm/arm/vgic/vgic-kvm-device.c
+++ b/virt/kvm/arm/vgic/vgic-kvm-device.c
@@ -236,12 +236,13 @@  void kvm_register_vgic_device(unsigned long type)
  */
 static int vgic_attr_regs_access(struct kvm_device *dev,
 				 struct kvm_device_attr *attr,
-				 u32 *reg, bool is_write)
+				 u64 *reg, bool is_write)
 {
 	gpa_t addr;
 	int cpuid, ret, c;
 	struct kvm_vcpu *vcpu, *tmp_vcpu;
 	int vcpu_lock_idx = -1;
+	u32 tmp32;
 
 	cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >>
 		 KVM_DEV_ARM_VGIC_CPUID_SHIFT;
@@ -272,12 +273,19 @@  static int vgic_attr_regs_access(struct kvm_device *dev,
 		vcpu_lock_idx = c;
 	}
 
+	if (is_write)
+		tmp32 = *reg;
+
 	switch (attr->group) {
 	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
-		ret = vgic_v2_cpuif_uaccess(vcpu, is_write, addr, reg);
+		ret = vgic_v2_cpuif_uaccess(vcpu, is_write, addr, &tmp32);
+		if (!is_write)
+			*reg = tmp32;
 		break;
 	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
-		ret = vgic_v2_dist_uaccess(vcpu, is_write, addr, reg);
+		ret = vgic_v2_dist_uaccess(vcpu, is_write, addr, &tmp32);
+		if (!is_write)
+			*reg = tmp32;
 		break;
 	default:
 		ret = -EINVAL;
@@ -309,11 +317,13 @@  static int vgic_v2_set_attr(struct kvm_device *dev,
 	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: {
 		u32 __user *uaddr = (u32 __user *)(long)attr->addr;
-		u32 reg;
+		u32 tmp32;
+		u64 reg;
 
-		if (get_user(reg, uaddr))
+		if (get_user(tmp32, uaddr))
 			return -EFAULT;
 
+		reg = tmp32;
 		return vgic_attr_regs_access(dev, attr, &reg, true);
 	}
 	}
@@ -334,12 +344,14 @@  static int vgic_v2_get_attr(struct kvm_device *dev,
 	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: {
 		u32 __user *uaddr = (u32 __user *)(long)attr->addr;
-		u32 reg = 0;
+		u32 tmp32;
+		u64 reg;
 
 		ret = vgic_attr_regs_access(dev, attr, &reg, false);
 		if (ret)
 			return ret;
-		return put_user(reg, uaddr);
+		tmp32 = reg;
+		return put_user(tmp32, uaddr);
 	}
 	}