Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4fe21e4c authored by Rusty Russell's avatar Rusty Russell Committed by Christoffer Dall
Browse files

KVM: ARM: VFP userspace interface 



We use space #18 for floating point regs.

Reviewed-by: default avatarWill Deacon <will.deacon@arm.com>
Reviewed-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: default avatarChristoffer Dall <c.dall@virtualopensystems.com>
parent c27581ed

Documentation/virtual/kvm/api.txt

+6 −0
Original line number Diff line number Diff line
@@ -1808,6 +1808,12 @@ 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 <regno:12>



ARM 64-bit FP registers have the following id bit patterns:

  0x4002 0000 0012 0 <regno:12>



4.69 KVM_GET_ONE_REG



Capability: KVM_CAP_ONE_REG

arch/arm/include/uapi/asm/kvm.h

+12 −0
Original line number Diff line number Diff line
@@ -112,6 +112,18 @@ struct kvm_arch_memory_slot { 
#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

arch/arm/kvm/coproc.c

+178 −0
Original line number Diff line number Diff line
@@ -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"
@@ -653,6 +655,170 @@ 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;
@@ -661,6 +827,9 @@ 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);
@@ -677,6 +846,9 @@ 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);
@@ -788,6 +960,7 @@ 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);

}
@@ -808,6 +981,11 @@ 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);

}