Excerpts from Haren Myneni's message of June 13, 2021 9:00 pm: > > PowerVM introduces two different type of credits: Default and Quality > of service (QoS). > > The total number of default credits available on each LPAR depends > on CPU resources configured. But these credits can be shared or > over-committed across LPARs in shared mode which can result in > paste command failure (RMA_busy). To avoid NX HW contention, the > hypervisor ntroduces QoS credit type which makes sure guaranteed > access to NX esources. The system admins can assign QoS credits > or each LPAR via HMC. > > Default credit type is used to allocate a VAS window by default as > on PowerVM implementation. But the process can pass > VAS_TX_WIN_FLAG_QOS_CREDIT flag with VAS_TX_WIN_OPEN ioctl to open > QoS type window. > > Signed-off-by: Haren Myneni <haren@xxxxxxxxxxxxx> Flag name looks good now. Again I don't have the spec, so Acked-by: Nicholas Piggin <npiggin@xxxxxxxxx> Thanks, Nick > --- > arch/powerpc/include/uapi/asm/vas-api.h | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/include/uapi/asm/vas-api.h b/arch/powerpc/include/uapi/asm/vas-api.h > index ebd4b2424785..7c81301ecdba 100644 > --- a/arch/powerpc/include/uapi/asm/vas-api.h > +++ b/arch/powerpc/include/uapi/asm/vas-api.h > @@ -13,11 +13,15 @@ > #define VAS_MAGIC 'v' > #define VAS_TX_WIN_OPEN _IOW(VAS_MAGIC, 0x20, struct vas_tx_win_open_attr) > > +/* Flags to VAS TX open window ioctl */ > +/* To allocate a window with QoS credit, otherwise use default credit */ > +#define VAS_TX_WIN_FLAG_QOS_CREDIT 0x0000000000000001 > + > struct vas_tx_win_open_attr { > __u32 version; > __s16 vas_id; /* specific instance of vas or -1 for default */ > __u16 reserved1; > - __u64 flags; /* Future use */ > + __u64 flags; > __u64 reserved2[6]; > }; > > -- > 2.18.2 > > >