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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v10 07/12] xen/arm: add support for cache coloring configuration via device-tree
Add the "llc-colors" Device Tree attribute to express DomUs and Dom0less
color configurations.
Based on original work from: Luca Miccio <lucmiccio@xxxxxxxxx>
Signed-off-by: Carlo Nonato <carlo.nonato@xxxxxxxxxxxxxxx>
Signed-off-by: Marco Solieri <marco.solieri@xxxxxxxxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx> # non-Arm
---
v10:
- no changes
v9:
- use best-effort allocation in domain_set_llc_colors_from_str()
v8:
- fixed memory leak on error path of domain_set_llc_colors_from_str()
- realloc colors array after parsing from string to reduce memory usage
v7:
- removed alloc_colors() helper usage from domain_set_llc_colors_from_str()
v6:
- rewrote domain_set_llc_colors_from_str() to be more explicit
v5:
- static-mem check has been moved in a previous patch
- added domain_set_llc_colors_from_str() to set colors after domain creation
---
docs/misc/arm/device-tree/booting.txt | 4 +++
docs/misc/cache-coloring.rst | 48 +++++++++++++++++++++++++++
xen/arch/arm/dom0less-build.c | 10 ++++++
xen/common/llc-coloring.c | 41 +++++++++++++++++++++++
xen/include/xen/llc-coloring.h | 1 +
xen/include/xen/xmalloc.h | 12 +++++++
6 files changed, 116 insertions(+)
diff --git a/docs/misc/arm/device-tree/booting.txt
b/docs/misc/arm/device-tree/booting.txt
index 3a04f5c57f..9085645433 100644
--- a/docs/misc/arm/device-tree/booting.txt
+++ b/docs/misc/arm/device-tree/booting.txt
@@ -162,6 +162,10 @@ with the following properties:
An integer specifying the number of vcpus to allocate to the guest.
+- llc-colors
+ A string specifying the LLC color configuration for the guest.
+ Refer to docs/misc/cache_coloring.rst for syntax.
+
- vpl011
An empty property to enable/disable a virtual pl011 for the guest to
diff --git a/docs/misc/cache-coloring.rst b/docs/misc/cache-coloring.rst
index c5fb33996c..c14b6ee2f4 100644
--- a/docs/misc/cache-coloring.rst
+++ b/docs/misc/cache-coloring.rst
@@ -12,6 +12,7 @@ If needed, change the maximum number of colors with
``CONFIG_LLC_COLORS_ORDER=<n>``.
Runtime configuration is done via `Command line parameters`_.
+For DomUs follow `DomUs configuration`_.
Background
**********
@@ -147,6 +148,53 @@ LLC specs can be manually set via the above command line
parameters. This
bypasses any auto-probing and it's used to overcome failing situations, such as
flawed probing logic, or for debugging/testing purposes.
+DomUs configuration
+*******************
+
+DomUs colors can be set either in the ``xl`` configuration file (documentation
+at `docs/man/xl.cfg.pod.5.in`) or via Device Tree, also for Dom0less
+configurations (documentation at `docs/misc/arm/device-tree/booting.txt`) using
+the ``llc-colors`` option. For example:
+
+::
+
+ xen,xen-bootargs = "console=dtuart dtuart=serial0 dom0_mem=1G
dom0_max_vcpus=1 sched=null llc-coloring=on dom0-llc-colors=2-6";
+ xen,dom0-bootargs "console=hvc0 earlycon=xen earlyprintk=xen
root=/dev/ram0"
+
+ dom0 {
+ compatible = "xen,linux-zimage" "xen,multiboot-module";
+ reg = <0x0 0x1000000 0x0 15858176>;
+ };
+
+ dom0-ramdisk {
+ compatible = "xen,linux-initrd" "xen,multiboot-module";
+ reg = <0x0 0x2000000 0x0 20638062>;
+ };
+
+ domU0 {
+ #address-cells = <0x1>;
+ #size-cells = <0x1>;
+ compatible = "xen,domain";
+ memory = <0x0 0x40000>;
+ llc-colors = "4-8,10,11,12";
+ cpus = <0x1>;
+ vpl011 = <0x1>;
+
+ module@2000000 {
+ compatible = "multiboot,kernel", "multiboot,module";
+ reg = <0x2000000 0xffffff>;
+ bootargs = "console=ttyAMA0";
+ };
+
+ module@30000000 {
+ compatible = "multiboot,ramdisk", "multiboot,module";
+ reg = <0x3000000 0xffffff>;
+ };
+ };
+
+**Note:** If no color configuration is provided for a domain, the default one,
+which corresponds to all available colors is used instead.
+
Known issues and limitations
****************************
diff --git a/xen/arch/arm/dom0less-build.c b/xen/arch/arm/dom0less-build.c
index 67b1503647..49d1f14d65 100644
--- a/xen/arch/arm/dom0less-build.c
+++ b/xen/arch/arm/dom0less-build.c
@@ -817,6 +817,7 @@ void __init create_domUs(void)
bool iommu = false;
const struct dt_device_node *cpupool_node,
*chosen = dt_find_node_by_path("/chosen");
+ const char *llc_colors_str = NULL;
BUG_ON(chosen == NULL);
dt_for_each_child_node(chosen, node)
@@ -965,6 +966,10 @@ void __init create_domUs(void)
#endif
}
+ dt_property_read_string(node, "llc-colors", &llc_colors_str);
+ if ( !llc_coloring_enabled && llc_colors_str )
+ panic("'llc-colors' found, but LLC coloring is disabled\n");
+
/*
* The variable max_init_domid is initialized with zero, so here it's
* very important to use the pre-increment operator to call
@@ -975,6 +980,11 @@ void __init create_domUs(void)
panic("Error creating domain %s (rc = %ld)\n",
dt_node_name(node), PTR_ERR(d));
+ if ( llc_coloring_enabled &&
+ (rc = domain_set_llc_colors_from_str(d, llc_colors_str)) )
+ panic("Error initializing LLC coloring for domain %s (rc = %d)\n",
+ dt_node_name(node), rc);
+
d->is_console = true;
dt_device_set_used_by(node, d->domain_id);
diff --git a/xen/common/llc-coloring.c b/xen/common/llc-coloring.c
index 3cfd0ce78c..14e056fb10 100644
--- a/xen/common/llc-coloring.c
+++ b/xen/common/llc-coloring.c
@@ -5,6 +5,7 @@
* Copyright (C) 2024, Advanced Micro Devices, Inc.
* Copyright (C) 2024, Minerva Systems SRL
*/
+#include "xen/xmalloc.h"
#include <xen/guest_access.h>
#include <xen/keyhandler.h>
#include <xen/llc-coloring.h>
@@ -270,6 +271,46 @@ void domain_llc_coloring_free(struct domain *d)
xfree(__va(__pa(d->llc_colors)));
}
+int __init domain_set_llc_colors_from_str(struct domain *d, const char *str)
+{
+ int err;
+ unsigned int *colors, num_colors;
+
+ if ( !str )
+ {
+ domain_set_default_colors(d);
+ return 0;
+ }
+
+ colors = xmalloc_array(unsigned int, max_nr_colors);
+ if ( !colors )
+ return -ENOMEM;
+
+ err = parse_color_config(str, colors, max_nr_colors, &num_colors);
+ if ( err )
+ {
+ printk(XENLOG_ERR "Error parsing LLC color configuration");
+ xfree(colors);
+ return err;
+ }
+
+ if ( !check_colors(colors, num_colors) )
+ {
+ printk(XENLOG_ERR "%pd: bad LLC color config\n", d);
+ xfree(colors);
+ return -EINVAL;
+ }
+
+ /* Adjust the size cause it was initially set to max_nr_colors */
+ d->llc_colors = xrealloc_array(colors, num_colors);
+ if ( !d->llc_colors )
+ d->llc_colors = colors;
+
+ d->num_llc_colors = num_colors;
+
+ return 0;
+}
+
/*
* Local variables:
* mode: C
diff --git a/xen/include/xen/llc-coloring.h b/xen/include/xen/llc-coloring.h
index 657f4d0a10..76d3cbae0e 100644
--- a/xen/include/xen/llc-coloring.h
+++ b/xen/include/xen/llc-coloring.h
@@ -32,6 +32,7 @@ void arch_llc_coloring_init(void);
int dom0_set_llc_colors(struct domain *d);
int domain_set_llc_colors(struct domain *d,
const struct xen_domctl_set_llc_colors *config);
+int domain_set_llc_colors_from_str(struct domain *d, const char *str);
#endif /* __COLORING_H__ */
diff --git a/xen/include/xen/xmalloc.h b/xen/include/xen/xmalloc.h
index b903fa2e26..f0412fb4e0 100644
--- a/xen/include/xen/xmalloc.h
+++ b/xen/include/xen/xmalloc.h
@@ -37,6 +37,9 @@
((_type *)_xmalloc_array(sizeof(_type), __alignof__(_type), _num))
#define xzalloc_array(_type, _num) \
((_type *)_xzalloc_array(sizeof(_type), __alignof__(_type), _num))
+#define xrealloc_array(_ptr, _num) \
+ ((typeof(_ptr))_xrealloc_array(_ptr, sizeof(typeof(*(_ptr))), \
+ __alignof__(typeof(*(_ptr))), _num))
/* Allocate space for a structure with a flexible array of typed objects. */
#define xzalloc_flex_struct(type, field, nr) \
@@ -98,6 +101,15 @@ static inline void *_xzalloc_array(
return _xzalloc(size * num, align);
}
+static inline void *_xrealloc_array(
+ void *ptr, unsigned long size, unsigned long align, unsigned long num)
+{
+ /* Check for overflow. */
+ if ( size && num > UINT_MAX / size )
+ return NULL;
+ return _xrealloc(ptr, size * num, align);
+}
+
/*
* Pooled allocator interface.
*/
--
2.43.0
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