On Thu, 12 Jul 2012 15:24:44 +0930, Rusty Russell <rusty.russell at linaro.org> wrote:
> Hi all,
>
> This turned out to be a longer patch series than I expected.
> The idea is that qemu tells us exactly what CPU (and cpu features) the
> guest should have, and we tell it exactly what CP15 registers we have.
OK, I've pushed an updated series:
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux.git msr-ops
Rather than re-post all 17, here are the differences from the first
patches (see inter-diff below):
1) We now add a 'struct kvm_vcpu_init' rather than overload kvm_sregs
(thanks Alexander), and added the ioctl KVM_ARM_VCPU_INIT.
2) I add a new KVM_VCPU_GET_MSR_INDEX_LIST rather than abusing the
KVM_GET_VCPU_MSR_INDEX_LIST which x86 uses: ours is per-vcpu.
3) We return ENOENT for unknown CP registers, EINVAL for invalid
combinations.
4) WI/RAZ -> RAW/WI (Thanks Peter).
5) Remove num_features bit (it's redundant: just zero them all), and
drop to 7*32 feature bits.
Cheers,
Rusty.
diff --git a/arch/arm/include/asm/kvm.h b/arch/arm/include/asm/kvm.h
index 6838210..d040a2a 100644
--- a/arch/arm/include/asm/kvm.h
+++ b/arch/arm/include/asm/kvm.h
@@ -62,10 +62,12 @@ struct kvm_regs {
/* Supported Processor Types */
#define KVM_ARM_TARGET_CORTEX_A15 (0xC0F)
-struct kvm_sregs {
+struct kvm_vcpu_init {
__u32 target;
- __u32 num_features;
- __u32 features[14];
+ __u32 features[7];
+};
+
+struct kvm_sregs {
};
struct kvm_fpu {
@@ -83,7 +85,7 @@ struct kvm_sync_regs {
struct kvm_arch_memory_slot {
};
-/* Exactly like x86. */
+/* Based on x86, but we use KVM_GET_VCPU_MSR_INDEX_LIST. */
struct kvm_msr_entry {
__u32 index;
__u32 reserved;
@@ -98,7 +100,7 @@ struct kvm_msrs {
struct kvm_msr_entry entries[0];
};
-/* for KVM_GET_MSR_INDEX_LIST */
+/* for KVM_VCPU_GET_MSR_INDEX_LIST */
struct kvm_msr_list {
__u32 nmsrs; /* number of msrs in entries */
__u32 indices[0];
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index a8dd6a0..bbe5617 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -180,4 +180,6 @@ static inline int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
struct kvm_vcpu *kvm_arm_get_running_vcpu(void);
struct kvm_vcpu __percpu **kvm_get_running_vcpus(void);
+int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
+ const struct kvm_vcpu_init *init);
#endif /* __ARM_KVM_HOST_H__ */
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 15283c9..c9a3770 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -567,7 +567,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
int exit_reason;
sigset_t sigsaved;
- /* Make sure they initialize the vcpu with KVM_SET_SREGS */
+ /* Make sure they initialize the vcpu with KVM_ARM_VCPU_INIT */
if (unlikely(!vcpu->arch.target))
return -ENOEXEC;
@@ -730,7 +730,15 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
return kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, &irq_event);
}
#endif
- case KVM_GET_MSR_INDEX_LIST: {
+ case KVM_ARM_VCPU_INIT: {
+ struct kvm_vcpu_init init;
+
+ if (copy_from_user(&init, argp, sizeof init))
+ return -EFAULT;
+
+ return kvm_vcpu_set_target(vcpu, &init);
+ }
+ case KVM_VCPU_GET_MSR_INDEX_LIST: {
struct kvm_msr_list __user *user_msr_list = argp;
struct kvm_msr_list msr_list;
unsigned n;
diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c
index e58d712..79c16c5 100644
--- a/arch/arm/kvm/coproc.c
+++ b/arch/arm/kvm/coproc.c
@@ -232,7 +232,7 @@ static bool access_dcsw(struct kvm_vcpu *vcpu,
* NAKed, so it will read the PMCR anyway.
*
* Therefore we tell the guest we have 0 counters. Unfortunately, we
- * must always support PMCCNTR (the cycle counter): we just WI/RAZ for
+ * must always support PMCCNTR (the cycle counter): we just RAZ/WI for
* all PM registers, which doesn't crash the guest kernel at least.
*/
static bool pm_fake(struct kvm_vcpu *vcpu,
@@ -683,7 +683,7 @@ static int get_fixed_cp15(u32 index, u64 *val)
index_to_params(index, ¶ms);
r = find_reg(¶ms, fixed_cp15, ARRAY_SIZE(fixed_cp15));
if (!r)
- return -EINVAL;
+ return -ENOENT;
*val = r->val;
return 0;
@@ -697,7 +697,7 @@ static int set_fixed_cp15(u32 index, u64 val)
index_to_params(index, ¶ms);
r = find_reg(¶ms, fixed_cp15, ARRAY_SIZE(fixed_cp15));
if (!r)
- return -EINVAL;
+ return -ENOENT;
/* This is what we mean by fixed: you can't change it. */
if (r->val != val)
diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c
index af26de7..d842d28 100644
--- a/arch/arm/kvm/guest.c
+++ b/arch/arm/kvm/guest.c
@@ -122,43 +122,34 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs)
{
- unsigned int i;
-
- /* FIXME: Should get_sregs on uninit vcpu return best CPU we can do? */
- if (!vcpu->arch.target)
- return -EINVAL;
-
- sregs->target = vcpu->arch.target;
-
- BUILD_BUG_ON(NUM_FEATURES > sizeof(sregs->features) * 8);
- sregs->num_features = NUM_FEATURES;
-
- /* Note: sregs is already kzalloc'ed, so no need to zero. */
- for (i = 0; i < NUM_FEATURES; i++) {
- if (test_bit(i, vcpu->arch.features))
- sregs->features[i / 32] |= (1 << (i % 32));
- }
- return 0;
+ return -EINVAL;
}
int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs)
{
+ return -EINVAL;
+}
+
+int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
+ const struct kvm_vcpu_init *init)
+{
unsigned int i;
/* We can only do a cortex A15 for now. */
- if (sregs->target != kvm_target_cpu())
+ if (init->target != kvm_target_cpu())
return -EINVAL;
- if (sregs->num_features > NUM_FEATURES)
- return -E2BIG;
-
- vcpu->arch.target = sregs->target;
+ vcpu->arch.target = init->target;
bitmap_zero(vcpu->arch.features, NUM_FEATURES);
- for (i = 0; i < NUM_FEATURES; i++) {
- if (sregs->features[i / 32] & (1 << (i % 32)))
+ /* -ENOENT for unknown features, -EINVAL for invalid combinations. */
+ for (i = 0; i < ARRAY_SIZE(init->features)*8; i++) {
+ if (init->features[i / 32] & (1 << (i % 32))) {
+ if (i >= NUM_FEATURES)
+ return -ENOENT;
set_bit(i, vcpu->arch.features);
+ }
}
/* Now we know what it is, we can reset it. */
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index f978447..209b432 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -905,6 +905,8 @@ struct kvm_s390_ucas_mapping {
#define KVM_SET_ONE_REG _IOW(KVMIO, 0xac, struct kvm_one_reg)
/* VM is being stopped by host */
#define KVM_KVMCLOCK_CTRL _IO(KVMIO, 0xad)
+#define KVM_ARM_VCPU_INIT _IOW(KVMIO, 0xae, struct kvm_vcpu_init)
+#define KVM_VCPU_GET_MSR_INDEX_LIST _IOWR(KVMIO, 0xaf, struct kvm_msr_list)
#define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0)
#define KVM_DEV_ASSIGN_PCI_2_3 (1 << 1)
