| Message ID | 90328d5aa92016434f3061ec7cadc812ea2c5dbc.camel@linux.ibm.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | Enable VAS and NX-GZIP support on powerVM | expand |
Excerpts from Haren Myneni's message of April 18, 2021 7:06 am: > > pHyp 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, phyp > introduces QoS credit type which makes sure guaranteed access to NX > resources. The system admins can assign QoS credits for 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_WIN_QOS_CREDITS There's some interchanging of pHyp and PowerVM in the series. PowerVM is probably the better term to use, with uppercase P. Unless you mean PAPR or pseries etc. I think you can say the PAPR VAS spec has two different types of credits, rather than say a specific hypervisor is introducing them. > flag with VAS_TX_WIN_OPEN ioctl to open QoS type window. > > Signed-off-by: Haren Myneni <haren@linux.ibm.com> > --- > 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..eb7c8694174f 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 default credit is used */ > +#define VAS_WIN_QOS_CREDITS 0x0000000000000001 > + > struct vas_tx_win_open_attr { Some consistency of naming might help, VAS_TX_WIN_FLAG_QOS_CREDIT. > __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 > > >
On Mon, 2021-05-10 at 15:54 +1000, Nicholas Piggin wrote: > Excerpts from Haren Myneni's message of April 18, 2021 7:06 am: > > pHyp 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, phyp > > introduces QoS credit type which makes sure guaranteed access to NX > > resources. The system admins can assign QoS credits for 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_WIN_QOS_CREDITS > > There's some interchanging of pHyp and PowerVM in the series. > > PowerVM is probably the better term to use, with uppercase P. > Unless you mean PAPR or pseries etc. > > I think you can say the PAPR VAS spec has two different types of > credits, rather than say a specific hypervisor is introducing them. DEF and QoS credits types are introduced by the hypervisor, not VAS PAPR. We did not have these types on powerNV. > > > flag with VAS_TX_WIN_OPEN ioctl to open QoS type window. > > > > Signed-off-by: Haren Myneni <haren@linux.ibm.com> > > --- > > 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..eb7c8694174f 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 default credit > > is used */ > > +#define VAS_WIN_QOS_CREDITS 0x0000000000000001 > > + > > struct vas_tx_win_open_attr { > > Some consistency of naming might help, VAS_TX_WIN_FLAG_QOS_CREDIT. Sure, will change. > > > __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 > > > > > >
diff --git a/arch/powerpc/include/uapi/asm/vas-api.h b/arch/powerpc/include/uapi/asm/vas-api.h index ebd4b2424785..eb7c8694174f 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 default credit is used */ +#define VAS_WIN_QOS_CREDITS 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]; };
pHyp 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, phyp introduces QoS credit type which makes sure guaranteed access to NX resources. The system admins can assign QoS credits for 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_WIN_QOS_CREDITS flag with VAS_TX_WIN_OPEN ioctl to open QoS type window. Signed-off-by: Haren Myneni <haren@linux.ibm.com> --- arch/powerpc/include/uapi/asm/vas-api.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)