Currently the KVM_GET_FPU and KVM_SET_FPU ioctls return an EOPNOTSUPP
error on powerpc. This implements them for Book 3S processors. Since
those processors have more than just the 32 basic floating-point
registers, this extends the kvm_fpu structure to have space for the
additional registers -- the 32 vector registers (128 bits each) for
VMX/Altivec and the 32 additional 64-bit registers that were added
on POWER7 for the vector-scalar extension (VSX). It also adds a
`valid' field, which is a bitmap indicating which elements contain
valid data.
The layout of the floating-point register data in the vcpu struct is
mostly the same between different flavors of KVM on Book 3S processors,
but the set of supported registers may differ depending on what the
CPU hardware supports and how much is emulated. Therefore we have
a flavor-specific function to work out which set of registers to
supply for the get function.
On POWER7 processors using the Book 3S HV flavor of KVM, we save the
standard floating-point registers together with their corresponding
VSX extension register in the vcpu->arch.vsr[] array, since each
pair can be loaded or stored with one instruction. This is different
to other flavors of KVM, and to other processors (i.e. PPC970) with
HV KVM, which store the standard FPRs in vcpu->arch.fpr[]. To cope
with this, we use the kvmppc_core_get_fpu_valid() and
kvmppc_core_set_fpu_valid() functions to sync between the arch.fpr[]
and arch.vsr[] arrays as needed.
Signed-off-by: Paul Mackerras <paulus@xxxxxxxxx>
---
arch/powerpc/include/asm/kvm.h | 11 ++++++++
arch/powerpc/include/asm/kvm_ppc.h | 2 ++
arch/powerpc/kvm/book3s.c | 49 ++++++++++++++++++++++++++++++++++--
arch/powerpc/kvm/book3s_hv.c | 32 +++++++++++++++++++++++
arch/powerpc/kvm/book3s_pr.c | 19 ++++++++++++++
5 files changed, 111 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm.h b/arch/powerpc/include/asm/kvm.h
index 9557576..5792024 100644
--- a/arch/powerpc/include/asm/kvm.h
+++ b/arch/powerpc/include/asm/kvm.h
@@ -261,9 +261,20 @@ struct kvm_sregs {
};
struct kvm_fpu {
+ __u64 valid;
+ __u64 fpscr;
__u64 fpr[32];
+ __vector128 vr[32];
+ __u32 _pad[3];
+ __u32 vscr;
+ __u64 vsr[32];
};
+/* Values for kvm_fpu valid field */
+#define KVM_FPU_FPREGS 1 /* standard floating-point regs & FPSCR */
+#define KVM_FPU_VREGS 2 /* VMX/Altivec vector regs & VSCR */
+#define KVM_FPU_VSREGS 4 /* POWER7 vector/scalar additional regs */
+
struct kvm_debug_exit_arch {
};
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index c06a64b..5dccdc5 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -96,6 +96,8 @@ extern int kvmppc_core_vcpu_translate(struct kvm_vcpu *vcpu,
extern void kvmppc_core_vcpu_load(struct kvm_vcpu *vcpu, int cpu);
extern void kvmppc_core_vcpu_put(struct kvm_vcpu *vcpu);
+extern u64 kvmppc_core_get_fpu_valid(struct kvm_vcpu *vcpu);
+extern void kvmppc_core_set_fpu_valid(struct kvm_vcpu *vcpu, u64 valid);
extern int kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu);
extern int kvmppc_core_pending_dec(struct kvm_vcpu *vcpu);
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index e946665..c2278f6 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -477,12 +477,57 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
{
- return -ENOTSUPP;
+ u64 valid = kvmppc_core_get_fpu_valid(vcpu);
+
+ /* avoid leaking information to userspace */
+ memset(fpu, 0, sizeof(*fpu));
+
+ if (valid & KVM_FPU_FPREGS) {
+ memcpy(fpu->fpr, vcpu->arch.fpr, sizeof(fpu->fpr));
+ fpu->fpscr = vcpu->arch.fpscr;
+ }
+#ifdef CONFIG_ALTIVEC
+ if (valid & KVM_FPU_VREGS) {
+ memcpy(fpu->vr, vcpu->arch.vr, sizeof(fpu->vr));
+ fpu->vscr = vcpu->arch.vscr.u[3];
+ }
+#endif
+#ifdef CONFIG_VSX
+ if (valid & KVM_FPU_VSREGS) {
+ long i;
+
+ for (i = 0; i < ARRAY_SIZE(fpu->vsr); ++i)
+ fpu->vsr[i] = vcpu->arch.vsr[2*i + 1];
+ }
+#endif
+ fpu->valid = valid;
+ return 0;
}
int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
{
- return -ENOTSUPP;
+ u64 valid = fpu->valid;
+
+ if (valid & KVM_FPU_FPREGS) {
+ memcpy(vcpu->arch.fpr, fpu->fpr, sizeof(vcpu->arch.fpr));
+ vcpu->arch.fpscr = fpu->fpscr;
+ }
+#ifdef CONFIG_ALTIVEC
+ if (valid & KVM_FPU_VREGS) {
+ memcpy(vcpu->arch.vr, fpu->vr, sizeof(vcpu->arch.vr));
+ vcpu->arch.vscr.u[3] = fpu->vscr;
+ }
+#endif
+#ifdef CONFIG_VSX
+ if (valid & KVM_FPU_VSREGS) {
+ long i;
+
+ for (i = 0; i < ARRAY_SIZE(fpu->vsr); ++i)
+ vcpu->arch.vsr[2*i + 1] = fpu->vsr[i];
+ }
+#endif
+ kvmppc_core_set_fpu_valid(vcpu, valid);
+ return 0;
}
int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 7fe5c9a..2c2b6b9 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -677,6 +677,38 @@ int kvm_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
return r;
}
+u64 kvmppc_core_get_fpu_valid(struct kvm_vcpu *vcpu)
+{
+ u64 valid = KVM_FPU_FPREGS;
+
+#ifdef CONFIG_ALTIVEC
+ if (cpu_has_feature(CPU_FTR_ALTIVEC))
+ valid |= KVM_FPU_VREGS;
+#endif
+#ifdef CONFIG_VSX
+ if (cpu_has_feature(CPU_FTR_VSX)) {
+ long i;
+
+ for (i = 0; i < ARRAY_SIZE(vcpu->arch.fpr); ++i)
+ vcpu->arch.fpr[i] = vcpu->arch.vsr[2*i];
+ valid |= KVM_FPU_VSREGS;
+ }
+#endif
+ return valid;
+}
+
+void kvmppc_core_set_fpu_valid(struct kvm_vcpu *vcpu, u64 valid)
+{
+#ifdef CONFIG_VSX
+ if ((valid & KVM_FPU_FPREGS) && cpu_has_feature(CPU_FTR_VSX)) {
+ long i;
+
+ for (i = 0; i < ARRAY_SIZE(vcpu->arch.fpr); ++i)
+ vcpu->arch.vsr[2*i] = vcpu->arch.fpr[i];
+ }
+#endif
+}
+
int kvmppc_core_check_processor_compat(void)
{
if (cpu_has_feature(CPU_FTR_HVMODE))
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index b3c584f..e3b81a2 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -978,6 +978,25 @@ int kvm_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
return r;
}
+u64 kvmppc_core_get_fpu_valid(struct kvm_vcpu *vcpu)
+{
+ u64 valid = KVM_FPU_FPREGS;
+
+#ifdef CONFIG_ALTIVEC
+ if (cpu_has_feature(CPU_FTR_ALTIVEC))
+ valid |= KVM_FPU_VREGS;
+#endif
+#ifdef CONFIG_VSX
+ if (cpu_has_feature(CPU_FTR_VSX))
+ valid |= KVM_FPU_VSREGS;
+#endif
+ return valid;
+}
+
+void kvmppc_core_set_fpu_valid(struct kvm_vcpu *vcpu, u64 valid)
+{
+}
+
int kvmppc_core_check_processor_compat(void)
{
return 0;
--
1.7.10.rc3.219.g53414
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