KVM: ARM: VFP userspace interface
We use space #18 for floating point regs.
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c
index 1827b64..d782638 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"
@@ -653,6 +655,170 @@
}
}
+#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 @@
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 @@
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 @@
{
return ARRAY_SIZE(invariant_cp15)
+ num_demux_regs()
+ + num_vfp_regs()
+ walk_cp15(vcpu, (u64 __user *)NULL);
}
@@ -808,6 +981,11 @@
return err;
uindices += err;
+ err = copy_vfp_regids(uindices);
+ if (err < 0)
+ return err;
+ uindices += err;
+
return write_demux_regids(uindices);
}