On Mon, Jan 07, 2019 at 08:10:04PM +0100, Cédric Le Goater wrote:
> At a VCPU level, the state of the thread context interrupt management
> registers needs to be collected. These registers are cached under the
> 'xive_saved_state.w01' field of the VCPU when the VPCU context is
> pulled from the HW thread. An OPAL call retrieves the backup of the
> IPB register in the NVT structure and merges it in the KVM state.
>
> The structures of the interface between QEMU and KVM provisions some
> extra room (two u64) for further extensions if more state needs to be
> transferred back to QEMU.
>
> Signed-off-by: Cédric Le Goater <clg@xxxxxxxx>
> ---
> arch/powerpc/include/asm/kvm_ppc.h | 5 ++
> arch/powerpc/include/uapi/asm/kvm.h | 2 +
> arch/powerpc/kvm/book3s.c | 24 +++++++++
> arch/powerpc/kvm/book3s_xive_native.c | 78 +++++++++++++++++++++++++++
> 4 files changed, 109 insertions(+)
>
> diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
> index 4cc897039485..49c488af168c 100644
> --- a/arch/powerpc/include/asm/kvm_ppc.h
> +++ b/arch/powerpc/include/asm/kvm_ppc.h
> @@ -270,6 +270,7 @@ union kvmppc_one_reg {
> u64 addr;
> u64 length;
> } vpaval;
> + u64 xive_timaval[4];
> };
>
> struct kvmppc_ops {
> @@ -603,6 +604,8 @@ extern void kvmppc_xive_native_cleanup_vcpu(struct kvm_vcpu *vcpu);
> extern void kvmppc_xive_native_init_module(void);
> extern void kvmppc_xive_native_exit_module(void);
> extern int kvmppc_xive_native_hcall(struct kvm_vcpu *vcpu, u32 cmd);
> +extern int kvmppc_xive_native_get_vp(struct kvm_vcpu *vcpu, union kvmppc_one_reg *val);
> +extern int kvmppc_xive_native_set_vp(struct kvm_vcpu *vcpu, union kvmppc_one_reg *val);
>
> #else
> static inline int kvmppc_xive_set_xive(struct kvm *kvm, u32 irq, u32 server,
> @@ -637,6 +640,8 @@ static inline void kvmppc_xive_native_init_module(void) { }
> static inline void kvmppc_xive_native_exit_module(void) { }
> static inline int kvmppc_xive_native_hcall(struct kvm_vcpu *vcpu, u32 cmd)
> { return 0; }
> +static inline int kvmppc_xive_native_get_vp(struct kvm_vcpu *vcpu, union kvmppc_one_reg *val) { return 0; }
> +static inline int kvmppc_xive_native_set_vp(struct kvm_vcpu *vcpu, union kvmppc_one_reg *val) { return -ENOENT; }
IIRC "VP" is the old name for "TCTX". Since we're using tctx in the
rest of the XIVE code, can we use it here as well.
> #endif /* CONFIG_KVM_XIVE */
>
> diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
> index 95302558ce10..3c958c39a782 100644
> --- a/arch/powerpc/include/uapi/asm/kvm.h
> +++ b/arch/powerpc/include/uapi/asm/kvm.h
> @@ -480,6 +480,8 @@ struct kvm_ppc_cpu_char {
> #define KVM_REG_PPC_ICP_PPRI_SHIFT 16 /* pending irq priority */
> #define KVM_REG_PPC_ICP_PPRI_MASK 0xff
>
> +#define KVM_REG_PPC_VP_STATE (KVM_REG_PPC | KVM_REG_SIZE_U256 | 0x8d)
> +
> /* Device control API: PPC-specific devices */
> #define KVM_DEV_MPIC_GRP_MISC 1
> #define KVM_DEV_MPIC_BASE_ADDR 0 /* 64-bit */
> diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
> index de7eed191107..5ad658077a35 100644
> --- a/arch/powerpc/kvm/book3s.c
> +++ b/arch/powerpc/kvm/book3s.c
> @@ -641,6 +641,18 @@ int kvmppc_get_one_reg(struct kvm_vcpu *vcpu, u64 id,
> *val = get_reg_val(id, kvmppc_xics_get_icp(vcpu));
> break;
> #endif /* CONFIG_KVM_XICS */
> +#ifdef CONFIG_KVM_XIVE
> + case KVM_REG_PPC_VP_STATE:
> + if (!vcpu->arch.xive_vcpu) {
> + r = -ENXIO;
> + break;
> + }
> + if (xive_enabled())
> + r = kvmppc_xive_native_get_vp(vcpu, val);
> + else
> + r = -ENXIO;
> + break;
> +#endif /* CONFIG_KVM_XIVE */
> case KVM_REG_PPC_FSCR:
> *val = get_reg_val(id, vcpu->arch.fscr);
> break;
> @@ -714,6 +726,18 @@ int kvmppc_set_one_reg(struct kvm_vcpu *vcpu, u64 id,
> r = kvmppc_xics_set_icp(vcpu, set_reg_val(id, *val));
> break;
> #endif /* CONFIG_KVM_XICS */
> +#ifdef CONFIG_KVM_XIVE
> + case KVM_REG_PPC_VP_STATE:
> + if (!vcpu->arch.xive_vcpu) {
> + r = -ENXIO;
> + break;
> + }
> + if (xive_enabled())
> + r = kvmppc_xive_native_set_vp(vcpu, val);
> + else
> + r = -ENXIO;
> + break;
> +#endif /* CONFIG_KVM_XIVE */
> case KVM_REG_PPC_FSCR:
> vcpu->arch.fscr = set_reg_val(id, *val);
> break;
> diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c
> index f4eb71eafc57..1aefb366df0b 100644
> --- a/arch/powerpc/kvm/book3s_xive_native.c
> +++ b/arch/powerpc/kvm/book3s_xive_native.c
> @@ -424,6 +424,84 @@ static int xive_native_validate_queue_size(u32 qsize)
> }
> }
>
> +#define TM_IPB_SHIFT 40
> +#define TM_IPB_MASK (((u64) 0xFF) << TM_IPB_SHIFT)
> +
> +int kvmppc_xive_native_get_vp(struct kvm_vcpu *vcpu, union kvmppc_one_reg *val)
> +{
> + struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
> + u64 opal_state;
> + int rc;
> +
> + if (!kvmppc_xive_enabled(vcpu))
> + return -EPERM;
> +
> + if (!xc)
> + return -ENOENT;
> +
> + /* Thread context registers. We only care about IPB and CPPR */
> + val->xive_timaval[0] = vcpu->arch.xive_saved_state.w01;
> +
> + /*
> + * Return the OS CAM line to print out the VP identifier in
> + * the QEMU monitor. This is not restored.
> + */
> + val->xive_timaval[1] = vcpu->arch.xive_cam_word;
> +
> + /* Get the VP state from OPAL */
> + rc = xive_native_get_vp_state(xc->vp_id, &opal_state);
> + if (rc)
> + return rc;
> +
> + /*
> + * Capture the backup of IPB register in the NVT structure and
> + * merge it in our KVM VP state.
> + *
> + * TODO: P10 support.
> + */
> + val->xive_timaval[0] |= cpu_to_be64(opal_state & TM_IPB_MASK);
> +
> + pr_devel("%s NSR=%02x CPPR=%02x IBP=%02x PIPR=%02x w01=%016llx w2=%08x opal=%016llx\n",
> + __func__,
> + vcpu->arch.xive_saved_state.nsr,
> + vcpu->arch.xive_saved_state.cppr,
> + vcpu->arch.xive_saved_state.ipb,
> + vcpu->arch.xive_saved_state.pipr,
> + vcpu->arch.xive_saved_state.w01,
> + (u32) vcpu->arch.xive_cam_word, opal_state);
> +
> + return 0;
> +}
> +
> +int kvmppc_xive_native_set_vp(struct kvm_vcpu *vcpu, union kvmppc_one_reg *val)
> +{
> + struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
> + struct kvmppc_xive *xive = vcpu->kvm->arch.xive;
> +
> + pr_devel("%s w01=%016llx vp=%016llx\n", __func__,
> + val->xive_timaval[0], val->xive_timaval[1]);
> +
> + if (!kvmppc_xive_enabled(vcpu))
> + return -EPERM;
> +
> + if (!xc || !xive)
> + return -ENOENT;
> +
> + /* We can't update the state of a "pushed" VCPU */
> + if (WARN_ON(vcpu->arch.xive_pushed))
> + return -EIO;
> +
> + /* Thread context registers. only restore IPB and CPPR ? */
> + vcpu->arch.xive_saved_state.w01 = val->xive_timaval[0];
> +
> + /*
> + * There is no need to restore the XIVE internal state (IPB
> + * stored in the NVT) as the IPB register was merged in KVM VP
> + * state.
> + */
> + return 0;
> +}
> +
> static int kvmppc_xive_native_set_source(struct kvmppc_xive *xive, long irq,
> u64 addr)
> {
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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