diff mbox

[v2,12/14] KVM: ARM: VFP userspace interface

Message ID 20121001091125.49198.90819.stgit@ubuntu (mailing list archive)
State New, archived
Headers show

Commit Message

Christoffer Dall Oct. 1, 2012, 9:11 a.m. UTC
From: Rusty Russell <rusty.russell@linaro.org>

We use space #18 for floating point regs.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
---
 Documentation/virtual/kvm/api.txt |    6 +
 arch/arm/include/asm/kvm.h        |   12 ++
 arch/arm/kvm/coproc.c             |  178 +++++++++++++++++++++++++++++++++++++
 3 files changed, 196 insertions(+)

Comments

Peter Maydell Oct. 9, 2012, 6:11 p.m. UTC | #1
On 1 October 2012 10:11, Christoffer Dall <c.dall@virtualopensystems.com> wrote:
> From: Rusty Russell <rusty.russell@linaro.org>
> --- a/Documentation/virtual/kvm/api.txt
> +++ b/Documentation/virtual/kvm/api.txt
> @@ -1765,6 +1765,12 @@ ARM 64-bit CP15 registers have the following id bit patterns:
>  ARM CCSIDR registers are demultiplexed by CSSELR value:
>    0x4002 0000 0011 00 <csselr:8>
>
> +ARM 32-bit VFP control registers have the following id bit patterns:
> +  0x4002 0000 0012 1 <selector:3>
> +
> +ARM 64-bit FP registers have the following id bit patterns:
> +  0x4002 0000 0012 0 <selector:3>
> +

In the other entries in this section, <foo:3> indicates a 3 bit field.
But I think for these two it's trying to indicate a 3 byte field.
Compare the include file constants:

+#define KVM_REG_ARM_VFP                        (0x0012 <<
KVM_REG_ARM_COPROC_SHIFT)
+#define KVM_REG_ARM_VFP_MASK           0x000000000000FFFF
+#define KVM_REG_ARM_VFP_BASE_REG       0x0
+#define KVM_REG_ARM_VFP_FPSID          0x1000
+#define KVM_REG_ARM_VFP_FPSCR          0x1001

so eg the first control register is
 0x4002 0000 0012 1000
and the first D reg is
 0x4002 0000 0012 0000

So my guess is these should be <selector:12>
(or possibly even something slightly more specific than 'selector'
like '<regno:12>' ?)

-- PMM
Christoffer Dall Oct. 9, 2012, 6:13 p.m. UTC | #2
On Tue, Oct 9, 2012 at 2:11 PM, Peter Maydell <peter.maydell@linaro.org> wrote:
> On 1 October 2012 10:11, Christoffer Dall <c.dall@virtualopensystems.com> wrote:
>> From: Rusty Russell <rusty.russell@linaro.org>
>> --- a/Documentation/virtual/kvm/api.txt
>> +++ b/Documentation/virtual/kvm/api.txt
>> @@ -1765,6 +1765,12 @@ ARM 64-bit CP15 registers have the following id bit patterns:
>>  ARM CCSIDR registers are demultiplexed by CSSELR value:
>>    0x4002 0000 0011 00 <csselr:8>
>>
>> +ARM 32-bit VFP control registers have the following id bit patterns:
>> +  0x4002 0000 0012 1 <selector:3>
>> +
>> +ARM 64-bit FP registers have the following id bit patterns:
>> +  0x4002 0000 0012 0 <selector:3>
>> +
>
> In the other entries in this section, <foo:3> indicates a 3 bit field.
> But I think for these two it's trying to indicate a 3 byte field.
> Compare the include file constants:
>
> +#define KVM_REG_ARM_VFP                        (0x0012 <<
> KVM_REG_ARM_COPROC_SHIFT)
> +#define KVM_REG_ARM_VFP_MASK           0x000000000000FFFF
> +#define KVM_REG_ARM_VFP_BASE_REG       0x0
> +#define KVM_REG_ARM_VFP_FPSID          0x1000
> +#define KVM_REG_ARM_VFP_FPSCR          0x1001
>
> so eg the first control register is
>  0x4002 0000 0012 1000
> and the first D reg is
>  0x4002 0000 0012 0000
>
> So my guess is these should be <selector:12>
> (or possibly even something slightly more specific than 'selector'
> like '<regno:12>' ?)
>
right you are, I'll modify this.

Thanks,
-Christoffer
Rusty Russell Oct. 11, 2012, 1:42 a.m. UTC | #3
Christoffer Dall <c.dall@virtualopensystems.com> writes:
> On Tue, Oct 9, 2012 at 2:11 PM, Peter Maydell <peter.maydell@linaro.org> wrote:
>> On 1 October 2012 10:11, Christoffer Dall <c.dall@virtualopensystems.com> wrote:
>>> From: Rusty Russell <rusty.russell@linaro.org>
...
>>> +ARM 32-bit VFP control registers have the following id bit patterns:
>>> +  0x4002 0000 0012 1 <selector:3>
>>> +
>>> +ARM 64-bit FP registers have the following id bit patterns:
>>> +  0x4002 0000 0012 0 <selector:3>
>>> +
>>
>> In the other entries in this section, <foo:3> indicates a 3 bit field.
>> But I think for these two it's trying to indicate a 3 byte field.
...
> right you are, I'll modify this.

Thanks!
Rusty.
diff mbox

Patch

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 74223f3..7695425 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -1765,6 +1765,12 @@  ARM 64-bit CP15 registers have the following id bit patterns:
 ARM CCSIDR registers are demultiplexed by CSSELR value:
   0x4002 0000 0011 00 <csselr:8>
 
+ARM 32-bit VFP control registers have the following id bit patterns:
+  0x4002 0000 0012 1 <selector:3>
+
+ARM 64-bit FP registers have the following id bit patterns:
+  0x4002 0000 0012 0 <selector:3>
+
 4.69 KVM_GET_ONE_REG
 
 Capability: KVM_CAP_ONE_REG
diff --git a/arch/arm/include/asm/kvm.h b/arch/arm/include/asm/kvm.h
index 0ab12fd..b6eaf0c 100644
--- a/arch/arm/include/asm/kvm.h
+++ b/arch/arm/include/asm/kvm.h
@@ -95,6 +95,18 @@  struct kvm_reg_list {
 #define KVM_REG_ARM_DEMUX_VAL_MASK	0x00000000000000FF
 #define KVM_REG_ARM_DEMUX_VAL_SHIFT	0
 
+/* VFP registers: we could overload CP10 like ARM does, but that's ugly. */
+#define KVM_REG_ARM_VFP			(0x0012 << KVM_REG_ARM_COPROC_SHIFT)
+#define KVM_REG_ARM_VFP_MASK		0x000000000000FFFF
+#define KVM_REG_ARM_VFP_BASE_REG	0x0
+#define KVM_REG_ARM_VFP_FPSID		0x1000
+#define KVM_REG_ARM_VFP_FPSCR		0x1001
+#define KVM_REG_ARM_VFP_MVFR1		0x1006
+#define KVM_REG_ARM_VFP_MVFR0		0x1007
+#define KVM_REG_ARM_VFP_FPEXC		0x1008
+#define KVM_REG_ARM_VFP_FPINST		0x1009
+#define KVM_REG_ARM_VFP_FPINST2		0x100A
+
 
 /* KVM_IRQ_LINE irq field index values */
 #define KVM_ARM_IRQ_TYPE_SHIFT		24
diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c
index 7addf62..b8bddd7 100644
--- a/arch/arm/kvm/coproc.c
+++ b/arch/arm/kvm/coproc.c
@@ -26,6 +26,8 @@ 
 #include <asm/cacheflush.h>
 #include <asm/cputype.h>
 #include <trace/events/kvm.h>
+#include <asm/vfp.h>
+#include "../vfp/vfpinstr.h"
 
 #include "trace.h"
 #include "coproc.h"
@@ -652,6 +654,170 @@  static int demux_c15_set(u64 id, void __user *uaddr)
 	}
 }
 
+#ifdef CONFIG_VFPv3
+static const int vfp_sysregs[] = { KVM_REG_ARM_VFP_FPEXC,
+				   KVM_REG_ARM_VFP_FPSCR,
+				   KVM_REG_ARM_VFP_FPINST,
+				   KVM_REG_ARM_VFP_FPINST2,
+				   KVM_REG_ARM_VFP_MVFR0,
+				   KVM_REG_ARM_VFP_MVFR1,
+				   KVM_REG_ARM_VFP_FPSID };
+
+static unsigned int num_fp_regs(void)
+{
+	if (((fmrx(MVFR0) & MVFR0_A_SIMD_MASK) >> MVFR0_A_SIMD_BIT) == 2)
+		return 32;
+	else
+		return 16;
+}
+
+static unsigned int num_vfp_regs(void)
+{
+	/* Normal FP regs + control regs. */
+	return num_fp_regs() + ARRAY_SIZE(vfp_sysregs);
+}
+
+static int copy_vfp_regids(u64 __user *uindices)
+{
+	unsigned int i;
+	const u64 u32reg = KVM_REG_ARM | KVM_REG_SIZE_U32 | KVM_REG_ARM_VFP;
+	const u64 u64reg = KVM_REG_ARM | KVM_REG_SIZE_U64 | KVM_REG_ARM_VFP;
+
+	for (i = 0; i < num_fp_regs(); i++) {
+		if (put_user((u64reg | KVM_REG_ARM_VFP_BASE_REG) + i,
+			     uindices))
+			return -EFAULT;
+		uindices++;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(vfp_sysregs); i++) {
+		if (put_user(u32reg | vfp_sysregs[i], uindices))
+			return -EFAULT;
+		uindices++;
+	}
+
+	return num_vfp_regs();
+}
+
+static int vfp_get_reg(const struct kvm_vcpu *vcpu, u64 id, void __user *uaddr)
+{
+	u32 vfpid = (id & KVM_REG_ARM_VFP_MASK);
+	u32 val;
+
+	/* Fail if we have unknown bits set. */
+	if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK
+		   | ((1 << KVM_REG_ARM_COPROC_SHIFT)-1)))
+		return -ENOENT;
+
+	if (vfpid < num_fp_regs()) {
+		if (KVM_REG_SIZE(id) != 8)
+			return -ENOENT;
+		return reg_to_user(uaddr, &vcpu->arch.vfp_guest.fpregs[vfpid],
+				   id);
+	}
+
+	/* FP control registers are all 32 bit. */
+	if (KVM_REG_SIZE(id) != 4)
+		return -ENOENT;
+
+	switch (vfpid) {
+	case KVM_REG_ARM_VFP_FPEXC:
+		return reg_to_user(uaddr, &vcpu->arch.vfp_guest.fpexc, id);
+	case KVM_REG_ARM_VFP_FPSCR:
+		return reg_to_user(uaddr, &vcpu->arch.vfp_guest.fpscr, id);
+	case KVM_REG_ARM_VFP_FPINST:
+		return reg_to_user(uaddr, &vcpu->arch.vfp_guest.fpinst, id);
+	case KVM_REG_ARM_VFP_FPINST2:
+		return reg_to_user(uaddr, &vcpu->arch.vfp_guest.fpinst2, id);
+	case KVM_REG_ARM_VFP_MVFR0:
+		val = fmrx(MVFR0);
+		return reg_to_user(uaddr, &val, id);
+	case KVM_REG_ARM_VFP_MVFR1:
+		val = fmrx(MVFR1);
+		return reg_to_user(uaddr, &val, id);
+	case KVM_REG_ARM_VFP_FPSID:
+		val = fmrx(FPSID);
+		return reg_to_user(uaddr, &val, id);
+	default:
+		return -ENOENT;
+	}
+}
+
+static int vfp_set_reg(struct kvm_vcpu *vcpu, u64 id, const void __user *uaddr)
+{
+	u32 vfpid = (id & KVM_REG_ARM_VFP_MASK);
+	u32 val;
+
+	/* Fail if we have unknown bits set. */
+	if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK
+		   | ((1 << KVM_REG_ARM_COPROC_SHIFT)-1)))
+		return -ENOENT;
+
+	if (vfpid < num_fp_regs()) {
+		if (KVM_REG_SIZE(id) != 8)
+			return -ENOENT;
+		return reg_from_user(&vcpu->arch.vfp_guest.fpregs[vfpid],
+				     uaddr, id);
+	}
+
+	/* FP control registers are all 32 bit. */
+	if (KVM_REG_SIZE(id) != 4)
+		return -ENOENT;
+
+	switch (vfpid) {
+	case KVM_REG_ARM_VFP_FPEXC:
+		return reg_from_user(&vcpu->arch.vfp_guest.fpexc, uaddr, id);
+	case KVM_REG_ARM_VFP_FPSCR:
+		return reg_from_user(&vcpu->arch.vfp_guest.fpscr, uaddr, id);
+	case KVM_REG_ARM_VFP_FPINST:
+		return reg_from_user(&vcpu->arch.vfp_guest.fpinst, uaddr, id);
+	case KVM_REG_ARM_VFP_FPINST2:
+		return reg_from_user(&vcpu->arch.vfp_guest.fpinst2, uaddr, id);
+	/* These are invariant. */
+	case KVM_REG_ARM_VFP_MVFR0:
+		if (reg_from_user(&val, uaddr, id))
+			return -EFAULT;
+		if (val != fmrx(MVFR0))
+			return -EINVAL;
+		return 0;
+	case KVM_REG_ARM_VFP_MVFR1:
+		if (reg_from_user(&val, uaddr, id))
+			return -EFAULT;
+		if (val != fmrx(MVFR1))
+			return -EINVAL;
+		return 0;
+	case KVM_REG_ARM_VFP_FPSID:
+		if (reg_from_user(&val, uaddr, id))
+			return -EFAULT;
+		if (val != fmrx(FPSID))
+			return -EINVAL;
+		return 0;
+	default:
+		return -ENOENT;
+	}
+}
+#else /* !CONFIG_VFPv3 */
+static unsigned int num_vfp_regs(void)
+{
+	return 0;
+}
+
+static int copy_vfp_regids(u64 __user *uindices)
+{
+	return 0;
+}
+
+static int vfp_get_reg(const struct kvm_vcpu *vcpu, u64 id, void __user *uaddr)
+{
+	return -ENOENT;
+}
+
+static int vfp_set_reg(struct kvm_vcpu *vcpu, u64 id, const void __user *uaddr)
+{
+	return -ENOENT;
+}
+#endif /* !CONFIG_VFPv3 */
+
 int kvm_arm_coproc_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 {
 	const struct coproc_reg *r;
@@ -660,6 +826,9 @@  int kvm_arm_coproc_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
 		return demux_c15_get(reg->id, uaddr);
 
+	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_VFP)
+		return vfp_get_reg(vcpu, reg->id, uaddr);
+
 	r = index_to_coproc_reg(vcpu, reg->id);
 	if (!r)
 		return get_invariant_cp15(reg->id, uaddr);
@@ -676,6 +845,9 @@  int kvm_arm_coproc_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
 		return demux_c15_set(reg->id, uaddr);
 
+	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_VFP)
+		return vfp_set_reg(vcpu, reg->id, uaddr);
+
 	r = index_to_coproc_reg(vcpu, reg->id);
 	if (!r)
 		return set_invariant_cp15(reg->id, uaddr);
@@ -787,6 +959,7 @@  unsigned long kvm_arm_num_coproc_regs(struct kvm_vcpu *vcpu)
 {
 	return ARRAY_SIZE(invariant_cp15)
 		+ num_demux_regs()
+		+ num_vfp_regs()
 		+ walk_cp15(vcpu, (u64 __user *)NULL);
 }
 
@@ -807,6 +980,11 @@  int kvm_arm_copy_coproc_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
 		return err;
 	uindices += err;
 
+	err = copy_vfp_regids(uindices);
+	if (err < 0)
+		return err;
+	uindices += err;
+
 	return write_demux_regids(uindices);
 }