On 2/4/19 6:17 AM, David Gibson wrote:
> On Mon, Jan 07, 2019 at 07:43:25PM +0100, Cédric Le Goater wrote:
>> When migration of a VM is initiated, a first copy of the RAM is
>> transferred to the destination before the VM is stopped. At that time,
>> QEMU needs to perform a XIVE quiesce sequence to stop the flow of
>> event notifications and stabilize the EQs. The sources are masked and
>> the XIVE IC is synced with the KVM ioctl KVM_DEV_XIVE_GRP_SYNC.
>>
>
> Don't you also need to make sure the guests queue pages are marked
> dirty here, in case they were already migrated?
I have added an extra KVM service to mark the EQ pages dirty. That
might be overkill as it seems you are suggesting.
C.
>> Signed-off-by: Cédric Le Goater <clg@xxxxxxxx>
>> ---
>> arch/powerpc/include/uapi/asm/kvm.h | 1 +
>> arch/powerpc/kvm/book3s_xive_native.c | 32 +++++++++++++++++++++++++++
>> 2 files changed, 33 insertions(+)
>>
>> diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
>> index 6fc9660c5aec..f3b859223b80 100644
>> --- a/arch/powerpc/include/uapi/asm/kvm.h
>> +++ b/arch/powerpc/include/uapi/asm/kvm.h
>> @@ -681,6 +681,7 @@ struct kvm_ppc_cpu_char {
>> #define KVM_DEV_XIVE_GET_TIMA_FD 2
>> #define KVM_DEV_XIVE_VC_BASE 3
>> #define KVM_DEV_XIVE_GRP_SOURCES 2 /* 64-bit source attributes */
>> +#define KVM_DEV_XIVE_GRP_SYNC 3 /* 64-bit source attributes */
>>
>> /* Layout of 64-bit XIVE source attribute values */
>> #define KVM_XIVE_LEVEL_SENSITIVE (1ULL << 0)
>> diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c
>> index 4ca75aade069..a8052867afc1 100644
>> --- a/arch/powerpc/kvm/book3s_xive_native.c
>> +++ b/arch/powerpc/kvm/book3s_xive_native.c
>> @@ -459,6 +459,35 @@ static int kvmppc_xive_native_set_source(struct kvmppc_xive *xive, long irq,
>> return 0;
>> }
>>
>> +static int kvmppc_xive_native_sync(struct kvmppc_xive *xive, long irq, u64 addr)
>> +{
>> + struct kvmppc_xive_src_block *sb;
>> + struct kvmppc_xive_irq_state *state;
>> + struct xive_irq_data *xd;
>> + u32 hw_num;
>> + u16 src;
>> +
>> + pr_devel("%s irq=0x%lx\n", __func__, irq);
>> +
>> + sb = kvmppc_xive_find_source(xive, irq, &src);
>> + if (!sb)
>> + return -ENOENT;
>> +
>> + state = &sb->irq_state[src];
>> +
>> + if (!state->valid)
>> + return -ENOENT;
>> +
>> + arch_spin_lock(&sb->lock);
>> +
>> + kvmppc_xive_select_irq(state, &hw_num, &xd);
>> + xive_native_sync_source(hw_num);
>> + xive_native_sync_queue(hw_num);
>> +
>> + arch_spin_unlock(&sb->lock);
>> + return 0;
>> +}
>> +
>> static int kvmppc_xive_native_set_attr(struct kvm_device *dev,
>> struct kvm_device_attr *attr)
>> {
>> @@ -474,6 +503,8 @@ static int kvmppc_xive_native_set_attr(struct kvm_device *dev,
>> case KVM_DEV_XIVE_GRP_SOURCES:
>> return kvmppc_xive_native_set_source(xive, attr->attr,
>> attr->addr);
>> + case KVM_DEV_XIVE_GRP_SYNC:
>> + return kvmppc_xive_native_sync(xive, attr->attr, attr->addr);
>> }
>> return -ENXIO;
>> }
>> @@ -511,6 +542,7 @@ static int kvmppc_xive_native_has_attr(struct kvm_device *dev,
>> }
>> break;
>> case KVM_DEV_XIVE_GRP_SOURCES:
>> + case KVM_DEV_XIVE_GRP_SYNC:
>> if (attr->attr >= KVMPPC_XIVE_FIRST_IRQ &&
>> attr->attr < KVMPPC_XIVE_NR_IRQS)
>> return 0;
>
