Various spelling mistakes in comments.
Detected with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220430185654.5855-1-Julia.Lawall@inria.fr
The user can change the QoS credits dynamically with the
management console interface which notifies OS with sysfs. After
returning from the OS interface successfully, the management
console updates the hypervisor. Since the VAS capabilities in
the hypervisor is not updated when the OS gets the update,
the kernel is using the old total credits value from the
hypervisor. Fix this issue by using the new QoS credits
from the userspace instead of depending on VAS capabilities
from the hypervisor.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/76d156f8af1e03cc09369d68e0bfad0c40031bcc.camel@linux.ibm.com
Since the VAS windows belong to the VAS hardware resource, the
hypervisor expects the partition to close them on source partition
and reopen them after the partition migrated on the destination
machine.
This handler is called before pseries_suspend() to close these
windows and again invoked after migration. All active windows
for both default and QoS types will be closed and mark them
inactive and reopened after migration with this handler.
During the migration, the user space receives paste instruction
failure if it issues copy/paste on these inactive windows.
The current migration implementation does not freeze the user
space and applications can continue to open VAS windows while
migration is in progress. So when the migration_in_progress flag
is set, VAS open window API returns -EBUSY.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/05e45ff4f8babd2490ccb7ae923884f4aa21a7e5.camel@linux.ibm.com
VAS is a hardware engine stays on the chip. So when the partition
migrates, all VAS windows on the source system have to be closed
and reopen them on the destination after migration.
The kernel has to consider both DLPAR CPU and migration events to
take action on VAS windows. So using VAS_WIN_NO_CRED_CLOSE and
VAS_WIN_MIGRATE_CLOSE status bits and windows will be reopened
after migration only after both status bits are cleared.
This patch make changes to the current reconfig_open/close_windows
functions to support migration:
- Set VAS_WIN_MIGRATE_CLOSE to the window status when closes and
reopen windows with the same status during resume.
- Continue to close all windows even if deallocate HCALL failed
(should not happen) since no way to stop migration with the
current LPM implementation.
- If the DLPAR CPU event happens while migration is in progress,
set VAS_WIN_NO_CRED_CLOSE to the window status. Close window
happens with the first event (migration or DLPAR) and Reopen
window happens only with the last event (migration or DLPAR).
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0aad580387cb58379496b4cbbd7c5596e9ea70be.camel@linux.ibm.com
The coprocessor capabilities struct is used to get default and
QoS capabilities from the hypervisor during init, DLPAR event and
migration. So instead of allocating this struct for each event,
define global struct and reuse it which allows the migration code
to avoid adding an error path.
Also disable copy/paste feature flag if any capabilities HCALL
is failed.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/57da6a270fcb9308cd57be7c88037029343080f7.camel@linux.ibm.com
pseries supports two types of credits - Default (uses normal priority
FIFO) and Qality of service (QoS uses high priority FIFO). The user
decides the number of QoS credits and sets this value with HMC
interface. The total credits for QoS capabilities can be changed
dynamically with HMC interface which invokes drmgr to communicate
to the kernel.
This patch creats 'update_total_credits' entry for QoS capabilities
so that drmgr command can write the new target QoS credits in sysfs.
Instead of using this value, the kernel gets the new QoS capabilities
from the hypervisor whenever update_total_credits is updated to make
sure sync with the QoS target credits in the hypervisor.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b01ef31a0f964686d00243e7de7f09c73c07e69e.camel@linux.ibm.com
The hypervisor provides the available VAS GZIP capabilities such
as default or QoS window type and the target available credits in
each type. This patch creates sysfs entries and exports the target,
used and the available credits for each feature.
This interface can be used by the user space to determine the credits
usage or to set the target credits in the case of QoS type (for DLPAR).
/sys/devices/vas/vas0/gzip/default_capabilities (default GZIP capabilities)
nr_total_credits /* Total credits available. Can be
/* changed with DLPAR operation */
nr_used_credits /* Used credits */
/sys/devices/vas/vas0/gzip/qos_capabilities (QoS GZIP capabilities)
nr_total_credits
nr_used_credits
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/702d8b626ebfac2b52f4995eebeafe1c9a6fcb75.camel@linux.ibm.com
VAS windows can be closed in the hypervisor due to lost credits
when the core is removed and the kernel gets fault for NX
requests on these inactive windows. If the NX requests are
issued on these inactive windows, OS gets page faults and the
paste failure will be returned to the user space. If the lost
credits are available later with core add, reopen these windows
and set them active. Later when the OS sees page faults on these
active windows, it creates mapping on the new paste address.
Then the user space can continue to use these windows and send
HW compression requests to NX successfully.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d9f360e21355e6826142c81146acfa9b60bc7ecc.camel@linux.ibm.com
The hypervisor assigns vas credits (windows) for each LPAR based
on the number of cores configured in that system. The OS is
expected to release credits when cores are removed, and may
allocate more when cores are added. So there is a possibility of
using excessive credits (windows) in the LPAR and the hypervisor
expects the system to close the excessive windows so that NX load
can be equally distributed across all LPARs in the system.
When the OS closes the excessive windows in the hypervisor,
it sets the window status inactive and invalidates window
virtual address mapping. The user space receives paste instruction
failure if any NX requests are issued on the inactive window.
Then the user space can use with the available open windows or
retry NX requests until this window active again.
This patch also adds the notifier for core removal/add to close
windows in the hypervisor if the system lost credits (core
removal) and reopen windows in the hypervisor when the previously
lost credits are available.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/108928f9c00a48cc6a722315d482d07cf66acf5a.camel@linux.ibm.com
The kernel sets the VAS window with PID when it is opened in
the hypervisor. During DLPAR operation, windows can be closed and
reopened in the hypervisor when the credit is available. So saves
this PID in pseries_vas_window struct when the window is opened
initially and reuse it later during DLPAR operation.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a57cbe6d292fe49ad55a0b49c5679d6a24d8fe73.camel@linux.ibm.com
nr_total/nr_used_credits provides credits usage to user space
via sysfs and the same interface can be used on PowerNV in
future. Changed with proper naming so that applicable on both
pseries and PowerNV.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f4313e9f198ee4f8d4fa4d015d8d1873e17851e6.camel@linux.ibm.com
Some functions defined in 'arch/powerpc/platforms/pseries' are
deserving of an `__init` macro attribute. These functions are only
called by other initialization functions and therefore should inherit
the attribute.
Also, change function declarations in header files to include `__init`.
Signed-off-by: Nick Child <nick.child@ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211216220035.605465-13-nick.child@ibm.com
KVM does not support VAS so guests always print a useless error on boot
vas: HCALL(398) error -2, query_type 0, result buffer 0x57f2000
Change this to only print the message if the error is not H_FUNCTION.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211126052133.1664375-1-npiggin@gmail.com
There are patches in flight to break the dependency between asm/irq.h
and linux/irqdomain.h, which would break compilation of vas.c because it
needs the declaration of irq_create_mapping() etc.
So add an explicit include of irqdomain.h to avoid that becoming a
problem in future.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210625045337.3197833-1-mpe@ellerman.id.au
NX generates an interrupt when sees a fault on the user space
buffer and the hypervisor forwards that interrupt to OS. Then
the kernel handles the interrupt by issuing H_GET_NX_FAULT hcall
to retrieve the fault CRB information.
This patch also adds changes to setup and free IRQ per each
window and also handles the fault by updating the CSB.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b8fc66dcb783d06a099a303e5cfc69087bb3357a.camel@linux.ibm.com
This patch adds VAS window allocatioa/close with the corresponding
hcalls. Also changes to integrate with the existing user space VAS
API and provide register/unregister functions to NX pseries driver.
The driver register function is used to create the user space
interface (/dev/crypto/nx-gzip) and unregister to remove this entry.
The user space process opens this device node and makes an ioctl
to allocate VAS window. The close interface is used to deallocate
window.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e8d956bace3f182c4d2e66e343ff37cb0391d1fd.camel@linux.ibm.com
The hypervisor provides VAS capabilities for GZIP default and QoS
features. These capabilities gives information for the specific
features such as total number of credits available in LPAR,
maximum credits allowed per window, maximum credits allowed in
LPAR, whether usermode copy/paste is supported, and etc.
This patch adds the following:
- Retrieve all features that are provided by hypervisor using
H_QUERY_VAS_CAPABILITIES hcall with 0 as feature type.
- Retrieve capabilities for the specific feature using the same
hcall and the feature type (1 for QoS and 2 for default type).
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/177c88608cb88f7b87d1c546103f18cec6c056b4.camel@linux.ibm.com
This patch adds the following hcall wrapper functions to allocate,
modify and deallocate VAS windows, and retrieve VAS capabilities.
H_ALLOCATE_VAS_WINDOW: Allocate VAS window
H_DEALLOCATE_VAS_WINDOW: Close VAS window
H_MODIFY_VAS_WINDOW: Setup window before using
H_QUERY_VAS_CAPABILITIES: Get VAS capabilities
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/40fb02a4d56ca4e240b074a15029082055be5997.camel@linux.ibm.com
