On Wed, Oct 11, 2023 at 10:13:31AM -0500, Ninad Palsule wrote: > This is a part of patchset where scratchpad is introduced. > > The scratchpad provides a set of non-functional registers. The firmware > is free to use them, hardware does not support any special management > support. The scratchpad registers can be read or written from LBUS > slave. > > In this model, The LBUS device is parent for the scratchpad. > > Signed-off-by: Andrew Jeffery <and...@aj.id.au> > Signed-off-by: Cédric Le Goater <c...@kaod.org> > Signed-off-by: Ninad Palsule <ni...@linux.ibm.com> > --- > v2: > - Incorporated Joel's review comments. > v5: > - Incorporated review comments by Cedric. > --- > include/hw/fsi/engine-scratchpad.h | 33 ++++++++++ > hw/fsi/engine-scratchpad.c | 99 ++++++++++++++++++++++++++++++ > hw/fsi/Kconfig | 4 ++ > hw/fsi/meson.build | 1 + > hw/fsi/trace-events | 2 + > 5 files changed, 139 insertions(+) > create mode 100644 include/hw/fsi/engine-scratchpad.h > create mode 100644 hw/fsi/engine-scratchpad.c > create mode 100644 hw/fsi/trace-events > > diff --git a/include/hw/fsi/engine-scratchpad.h > b/include/hw/fsi/engine-scratchpad.h > new file mode 100644 > index 0000000000..17e9570c5c > --- /dev/null > +++ b/include/hw/fsi/engine-scratchpad.h > @@ -0,0 +1,33 @@ > +/* > + * SPDX-License-Identifier: GPL-2.0-or-later > + * Copyright (C) 2023 IBM Corp. > + * > + * IBM scratchpad engne > + */ > +#ifndef FSI_ENGINE_SCRATCHPAD_H > +#define FSI_ENGINE_SCRATCHPAD_H > + > +#include "qemu/bitops.h" > + > +#include "hw/fsi/lbus.h" > + > +#define ENGINE_CONFIG_NEXT BE_BIT(0) > +#define ENGINE_CONFIG_VPD BE_BIT(1) > +#define ENGINE_CONFIG_SLOTS BE_GENMASK(8, 15) > +#define ENGINE_CONFIG_VERSION BE_GENMASK(16, 19) > +#define ENGINE_CONFIG_TYPE BE_GENMASK(20, 27) > +#define ENGINE_CONFIG_TYPE_PEEK (0x02 << 4) > +#define ENGINE_CONFIG_TYPE_FSI (0x03 << 4) > +#define ENGINE_CONFIG_TYPE_SCRATCHPAD (0x06 << 4) > +#define ENGINE_CONFIG_CRC BE_GENMASK(28, 31) > + > +#define TYPE_SCRATCHPAD "scratchpad" > +#define SCRATCHPAD(obj) OBJECT_CHECK(ScratchPad, (obj), TYPE_SCRATCHPAD) > + > +typedef struct ScratchPad { > + FSILBusDevice parent; > + > + uint32_t reg; > +} ScratchPad; > + > +#endif /* FSI_ENGINE_SCRATCHPAD_H */ > diff --git a/hw/fsi/engine-scratchpad.c b/hw/fsi/engine-scratchpad.c > new file mode 100644 > index 0000000000..60f678eec4 > --- /dev/null > +++ b/hw/fsi/engine-scratchpad.c > @@ -0,0 +1,99 @@ > +/* > + * SPDX-License-Identifier: GPL-2.0-or-later > + * Copyright (C) 2023 IBM Corp. > + * > + * IBM scratchpad engine > + */ > + > +#include "qemu/osdep.h" > + > +#include "qapi/error.h" > +#include "qemu/log.h" > +#include "trace.h" > + > +#include "hw/fsi/engine-scratchpad.h" > + > +static uint64_t scratchpad_read(void *opaque, hwaddr addr, unsigned size) > +{ > + ScratchPad *s = SCRATCHPAD(opaque); > + > + trace_scratchpad_read(addr, size); > + > + if (addr) { > + qemu_log_mask(LOG_GUEST_ERROR, > + "%s: Out of bounds read: 0x%"HWADDR_PRIx" for %u\n", > + __func__, addr, size);
We already have a trace point in the line above. I don't think we should be unconditionally logging errors like this, as this becomes a guest triggerable denial of service on the host log collector for the guest. eg it could flood the logfile connected to stderr with unlimited data by repeatedly doing bad reads/writes. > + return 0; > + } > + > + return s->reg; > +} > + > +static void scratchpad_write(void *opaque, hwaddr addr, uint64_t data, > + unsigned size) > +{ > + ScratchPad *s = SCRATCHPAD(opaque); > + > + trace_scratchpad_write(addr, size, data); > + > + if (addr) { > + qemu_log_mask(LOG_GUEST_ERROR, > + "%s: Out of bounds write: 0x%"HWADDR_PRIx" for %u\n", > + __func__, addr, size); > + return; > + } > + > + s->reg = data; > +} > + > +static const struct MemoryRegionOps scratchpad_ops = { > + .read = scratchpad_read, > + .write = scratchpad_write, > + .endianness = DEVICE_BIG_ENDIAN, > +}; > + > +static void scratchpad_realize(DeviceState *dev, Error **errp) > +{ > + FSILBusDevice *ldev = FSI_LBUS_DEVICE(dev); > + > + memory_region_init_io(&ldev->iomem, OBJECT(ldev), &scratchpad_ops, > + ldev, TYPE_SCRATCHPAD, 0x400); > +} > + > +static void scratchpad_reset(DeviceState *dev) > +{ > + ScratchPad *s = SCRATCHPAD(dev); > + > + s->reg = 0; > +} > + > +static void scratchpad_class_init(ObjectClass *klass, void *data) > +{ > + DeviceClass *dc = DEVICE_CLASS(klass); > + FSILBusDeviceClass *ldc = FSI_LBUS_DEVICE_CLASS(klass); > + > + dc->realize = scratchpad_realize; > + dc->reset = scratchpad_reset; > + > + ldc->config = > + ENGINE_CONFIG_NEXT /* valid */ > + | 0x00010000 /* slots */ > + | 0x00001000 /* version */ > + | ENGINE_CONFIG_TYPE_SCRATCHPAD /* type */ > + | 0x00000007; /* crc */ More common QEMU style would be for the "|" to be on the end of line rather than start. End of line: $ git grep '.*\s|\s*$' "*.c" | wc -l 5381 Start of line: $ git grep '^\s*|\s.*' "*.c" | wc -l 581 > +} > + > +static const TypeInfo scratchpad_info = { > + .name = TYPE_SCRATCHPAD, > + .parent = TYPE_FSI_LBUS_DEVICE, > + .instance_size = sizeof(ScratchPad), > + .class_init = scratchpad_class_init, > + .class_size = sizeof(FSILBusDeviceClass), > +}; > + > +static void scratchpad_register_types(void) > +{ > + type_register_static(&scratchpad_info); > +} > + > +type_init(scratchpad_register_types); > diff --git a/hw/fsi/Kconfig b/hw/fsi/Kconfig > index e650c660f0..f7c7fd1b28 100644 > --- a/hw/fsi/Kconfig > +++ b/hw/fsi/Kconfig > @@ -1,2 +1,6 @@ > +config FSI_SCRATCHPAD > + bool > + select FSI_LBUS > + > config FSI_LBUS > bool > diff --git a/hw/fsi/meson.build b/hw/fsi/meson.build > index 4074d3a7d2..d45a98c223 100644 > --- a/hw/fsi/meson.build > +++ b/hw/fsi/meson.build > @@ -1 +1,2 @@ > system_ss.add(when: 'CONFIG_FSI_LBUS', if_true: files('lbus.c')) > +system_ss.add(when: 'CONFIG_FSI_SCRATCHPAD', if_true: > files('engine-scratchpad.c')) > diff --git a/hw/fsi/trace-events b/hw/fsi/trace-events > new file mode 100644 > index 0000000000..97fd070354 > --- /dev/null > +++ b/hw/fsi/trace-events > @@ -0,0 +1,2 @@ > +scratchpad_read(uint64_t addr, uint32_t size) "@0x%" PRIx64 " size=%d" > +scratchpad_write(uint64_t addr, uint32_t size, uint64_t data) "@0x%" PRIx64 > " size=%d value=0x%"PRIx64 > -- > 2.39.2 > With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|