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KVM: PPC: Book3S HV: XIVE: Add get/set accessors for the VP XIVE state

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The state of the thread interrupt management registers needs to be
collected for migration. 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 underlying XIVE NVT structure and merges it in the
KVM state.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This commit is contained in:
Cédric Le Goater 2019-04-18 12:39:35 +02:00 committed by Paul Mackerras
parent e6714bd167
commit e4945b9da5
6 changed files with 131 additions and 0 deletions
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1
Documentation/virtual/kvm/api.txt
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@ -1985,6 +1985,7 @@ registers, find a list below:
PPC | KVM_REG_PPC_TLB3PS | 32
PPC | KVM_REG_PPC_EPTCFG | 32
PPC | KVM_REG_PPC_ICP_STATE | 64
PPC | KVM_REG_PPC_VP_STATE | 128
PPC | KVM_REG_PPC_TB_OFFSET | 64
PPC | KVM_REG_PPC_SPMC1 | 32
PPC | KVM_REG_PPC_SPMC2 | 32

17
Documentation/virtual/kvm/devices/xive.txt
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@ -107,6 +107,23 @@ the legacy interrupt mode, referred as XICS (POWER7/8).
-ENOENT: Unknown source number
-EINVAL: Not initialized source number
* VCPU state
The XIVE IC maintains VP interrupt state in an internal structure
called the NVT. When a VP is not dispatched on a HW processor
thread, this structure can be updated by HW if the VP is the target
of an event notification.
It is important for migration to capture the cached IPB from the NVT
as it synthesizes the priorities of the pending interrupts. We
capture a bit more to report debug information.
KVM_REG_PPC_VP_STATE (2 * 64bits)
bits: | 63 .... 32 | 31 .... 0 |
values: | TIMA word0 | TIMA word1 |
bits: | 127 .......... 64 |
values: | unused |
* Migration:
Saving the state of a VM using the XIVE native exploitation mode

11
arch/powerpc/include/asm/kvm_ppc.h
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@ -269,6 +269,7 @@ union kvmppc_one_reg {
u64 addr;
u64 length;
} vpaval;
u64 xive_timaval[2];
};
struct kvmppc_ops {
@ -604,6 +605,10 @@ extern int kvmppc_xive_native_connect_vcpu(struct kvm_device *dev,
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_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,
@ -636,6 +641,12 @@ static inline int kvmppc_xive_native_connect_vcpu(struct kvm_device *dev,
static inline void kvmppc_xive_native_cleanup_vcpu(struct kvm_vcpu *vcpu) { }
static inline void kvmppc_xive_native_init_module(void) { }
static inline void kvmppc_xive_native_exit_module(void) { }
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; }
#endif /* CONFIG_KVM_XIVE */

2
arch/powerpc/include/uapi/asm/kvm.h
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@ -482,6 +482,8 @@ 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_U128 | 0x8d)
/* Device control API: PPC-specific devices */
#define KVM_DEV_MPIC_GRP_MISC 1
#define KVM_DEV_MPIC_BASE_ADDR 0 /* 64-bit */

24
arch/powerpc/kvm/book3s.c
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@ -651,6 +651,18 @@ 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;
@ -724,6 +736,18 @@ 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;

76
arch/powerpc/kvm/book3s_xive_native.c
View File

@ -896,6 +896,82 @@ static int kvmppc_xive_native_create(struct kvm_device *dev, u32 type)
return ret;
}
/*
* Interrupt Pending Buffer (IPB) offset
*/
#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;
/* 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.
*/
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 -EBUSY;
/*
* Restore the thread context registers. IPB and CPPR should
* be the only ones that matter.
*/
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 when captured.
*/
return 0;
}
static int xive_native_debug_show(struct seq_file *m, void *private)
{
struct kvmppc_xive *xive = m->private;