diff mbox series

[v10,06/12] tools: add support for cache coloring configuration

Message ID 20241119141329.44221-7-carlo.nonato@minervasys.tech (mailing list archive)
State New
Headers show
Series Arm cache coloring | expand

Commit Message

Carlo Nonato Nov. 19, 2024, 2:13 p.m. UTC 
Add a new "llc_colors" parameter that defines the LLC color assignment for
a domain. The user can specify one or more color ranges using the same
syntax used everywhere else for color config described in the
documentation.
The parameter is defined as a list of strings that represent the color
ranges.

Documentation is also added.

Based on original work from: Luca Miccio <lucmiccio@gmail.com>

Signed-off-by: Carlo Nonato <carlo.nonato@minervasys.tech>
Signed-off-by: Marco Solieri <marco.solieri@minervasys.tech>
---
v10:
- no changes
v9:
- turned warning into error in case of coloring not enabled
v8:
- warn the user in case of coloring not supported at hypervisor level
v7:
- removed unneeded NULL check before xc_hypercall_buffer_free() in
  xc_domain_set_llc_colors()
v6:
- no edits
v5:
- added LIBXL_HAVE_BUILDINFO_LLC_COLORS
- moved color configuration in xc_domain_set_llc_colors() cause of the new
  hypercall
v4:
- removed overlapping color ranges checks during parsing
- moved hypercall buffer initialization in libxenctrl
---
 docs/man/xl.cfg.5.pod.in         |  6 +++++
 tools/include/libxl.h            |  5 +++++
 tools/include/xenctrl.h          |  9 ++++++++
 tools/libs/ctrl/xc_domain.c      | 35 +++++++++++++++++++++++++++++
 tools/libs/light/libxl_create.c  | 18 +++++++++++++++
 tools/libs/light/libxl_types.idl |  1 +
 tools/xl/xl_parse.c              | 38 +++++++++++++++++++++++++++++++-
 7 files changed, 111 insertions(+), 1 deletion(-)

Comments

Anthony PERARD Nov. 20, 2024, 4:25 p.m. UTC | #1 
Hi Carlo,

On Tue, Nov 19, 2024 at 03:13:23PM +0100, Carlo Nonato wrote:
> diff --git a/tools/libs/ctrl/xc_domain.c b/tools/libs/ctrl/xc_domain.c
> index e3538ec0ba..4ed339e6e4 100644
> --- a/tools/libs/ctrl/xc_domain.c
> +++ b/tools/libs/ctrl/xc_domain.c
> @@ -2195,6 +2195,41 @@ int xc_domain_soft_reset(xc_interface *xch,
>      domctl.domain = domid;
>      return do_domctl(xch, &domctl);
>  }
> +
> +int xc_domain_set_llc_colors(xc_interface *xch, uint32_t domid,
> +                             const unsigned int *llc_colors,

The hypercall seems to take a buffer of `uint32_t` for `llc_colors`, but
the parameter of the function is `unsigned int` instead, is there any
reason for them to be different?

> +                             unsigned int num_llc_colors)
> +{
> +    struct xen_domctl domctl = {};
> +    DECLARE_HYPERCALL_BUFFER(uint32_t, local);
> +    int ret = -1;
> +
> +    if ( num_llc_colors )
> +    {
> +        size_t bytes = sizeof(uint32_t) * num_llc_colors;
> +
> +        local = xc_hypercall_buffer_alloc(xch, local, bytes);
> +        if ( local == NULL )
> +        {
> +            PERROR("Could not allocate LLC colors for set_llc_colors");
> +            ret = -ENOMEM;

I think we are supposed to return -1 in case of error, see:
    https://elixir.bootlin.com/xen/v4.19.0/source/tools/include/xenctrl.h#L101

And there's nothing else to do, xc_hypercall_buffer_alloc() should
already have set `errno`, and PERROR() preserves it.

> +            goto out;
> +        }

Thanks,
Anthony PERARD Nov. 20, 2024, 4:48 p.m. UTC | #2 
On Tue, Nov 19, 2024 at 03:13:23PM +0100, Carlo Nonato wrote:
>  tools/libs/light/libxl_types.idl |  1 +

An other thing I've completely forgot, with this IDL changed there will
be a need to regen some other files in the repo, namely:
    tools/golang/xenlight/helpers.gen.go
    tools/golang/xenlight/types.gen.go

Running this following command should be enough, even if you don't have
golang installed.

    make -C tools/golang/xenlight helpers.gen.go types.gen.go

If you send an update of the patch series, it would be nice to include
the regenerated files.

Cheers,
Carlo Nonato Nov. 21, 2024, 11:48 a.m. UTC | #3 
Hi Anthony,

On Wed, Nov 20, 2024 at 5:25 PM Anthony PERARD
<anthony.perard@vates.tech> wrote:
>
> Hi Carlo,
>
> On Tue, Nov 19, 2024 at 03:13:23PM +0100, Carlo Nonato wrote:
> > diff --git a/tools/libs/ctrl/xc_domain.c b/tools/libs/ctrl/xc_domain.c
> > index e3538ec0ba..4ed339e6e4 100644
> > --- a/tools/libs/ctrl/xc_domain.c
> > +++ b/tools/libs/ctrl/xc_domain.c
> > @@ -2195,6 +2195,41 @@ int xc_domain_soft_reset(xc_interface *xch,
> >      domctl.domain = domid;
> >      return do_domctl(xch, &domctl);
> >  }
> > +
> > +int xc_domain_set_llc_colors(xc_interface *xch, uint32_t domid,
> > +                             const unsigned int *llc_colors,
>
> The hypercall seems to take a buffer of `uint32_t` for `llc_colors`, but
> the parameter of the function is `unsigned int` instead, is there any
> reason for them to be different?

I don't remember anymore, but I think it should be uint32_t also for the
parameter.

> > +                             unsigned int num_llc_colors)
> > +{
> > +    struct xen_domctl domctl = {};
> > +    DECLARE_HYPERCALL_BUFFER(uint32_t, local);
> > +    int ret = -1;
> > +
> > +    if ( num_llc_colors )
> > +    {
> > +        size_t bytes = sizeof(uint32_t) * num_llc_colors;
> > +
> > +        local = xc_hypercall_buffer_alloc(xch, local, bytes);
> > +        if ( local == NULL )
> > +        {
> > +            PERROR("Could not allocate LLC colors for set_llc_colors");
> > +            ret = -ENOMEM;
>
> I think we are supposed to return -1 in case of error, see:
>     https://elixir.bootlin.com/xen/v4.19.0/source/tools/include/xenctrl.h#L101
>
> And there's nothing else to do, xc_hypercall_buffer_alloc() should
> already have set `errno`, and PERROR() preserves it.

You're right.

>> > +            goto out;
> > +        }
>
> Thanks,
>
> --
>
> Anthony Perard | Vates XCP-ng Developer
>
> XCP-ng & Xen Orchestra - Vates solutions
> web: https://vates.tech

(answering the other mail)

On Wed, Nov 20, 2024 at 5:48 PM Anthony PERARD
<anthony.perard@vates.tech> wrote:
>
> On Tue, Nov 19, 2024 at 03:13:23PM +0100, Carlo Nonato wrote:
> >  tools/libs/light/libxl_types.idl |  1 +
>
> An other thing I've completely forgot, with this IDL changed there will
> be a need to regen some other files in the repo, namely:
>     tools/golang/xenlight/helpers.gen.go
>     tools/golang/xenlight/types.gen.go
>
> Running this following command should be enough, even if you don't have
> golang installed.
>
>     make -C tools/golang/xenlight helpers.gen.go types.gen.go
>
> If you send an update of the patch series, it would be nice to include
> the regenerated files.

Yes, will do that.

> Cheers,
>
> --
>
> Anthony Perard | Vates XCP-ng Developer
>
> XCP-ng & Xen Orchestra - Vates solutions
>
> web: https://vates.tech

 Thanks.

- Carlo
diff mbox series

Patch

diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in
index ac3f88fd57..8e1422104e 100644
--- a/docs/man/xl.cfg.5.pod.in
+++ b/docs/man/xl.cfg.5.pod.in
@@ -3074,6 +3074,12 @@  raised.
 
 =over 4
 
+=item B<llc_colors=[ "RANGE", "RANGE", ...]>
+
+Specify the Last Level Cache (LLC) color configuration for the guest.
+B<RANGE> can be either a single color value or a hypen-separated closed
+interval of colors (such as "0-4").
+
 =item B<nr_spis="NR_SPIS">
 
 An optional integer parameter specifying the number of SPIs (Shared
diff --git a/tools/include/libxl.h b/tools/include/libxl.h
index 8d32428ea9..f8fe4afd7d 100644
--- a/tools/include/libxl.h
+++ b/tools/include/libxl.h
@@ -1379,6 +1379,11 @@  void libxl_mac_copy(libxl_ctx *ctx, libxl_mac *dst, const libxl_mac *src);
  */
 #define LIBXL_HAVE_BUILDINFO_HVM_SYSTEM_FIRMWARE
 
+/*
+ * The libxl_domain_build_info has the llc_colors array.
+ */
+#define LIBXL_HAVE_BUILDINFO_LLC_COLORS 1
+
 /*
  * ERROR_REMUS_XXX error code only exists from Xen 4.5, Xen 4.6 and it
  * is changed to ERROR_CHECKPOINT_XXX in Xen 4.7
diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h
index 29617585c5..aa2b4b04f3 100644
--- a/tools/include/xenctrl.h
+++ b/tools/include/xenctrl.h
@@ -2667,6 +2667,15 @@  int xc_livepatch_replace(xc_interface *xch, char *name, uint32_t timeout, uint32
 int xc_domain_cacheflush(xc_interface *xch, uint32_t domid,
                          xen_pfn_t start_pfn, xen_pfn_t nr_pfns);
 
+/*
+ * Set LLC colors for a domain.
+ * It can only be used directly after domain creation. An attempt to use it
+ * afterwards will result in an error.
+ */
+int xc_domain_set_llc_colors(xc_interface *xch, uint32_t domid,
+                             const unsigned int *llc_colors,
+                             unsigned int num_llc_colors);
+
 #if defined(__arm__) || defined(__aarch64__)
 int xc_dt_overlay(xc_interface *xch, void *overlay_fdt,
                   uint32_t overlay_fdt_size, uint8_t overlay_op);
diff --git a/tools/libs/ctrl/xc_domain.c b/tools/libs/ctrl/xc_domain.c
index e3538ec0ba..4ed339e6e4 100644
--- a/tools/libs/ctrl/xc_domain.c
+++ b/tools/libs/ctrl/xc_domain.c
@@ -2195,6 +2195,41 @@  int xc_domain_soft_reset(xc_interface *xch,
     domctl.domain = domid;
     return do_domctl(xch, &domctl);
 }
+
+int xc_domain_set_llc_colors(xc_interface *xch, uint32_t domid,
+                             const unsigned int *llc_colors,
+                             unsigned int num_llc_colors)
+{
+    struct xen_domctl domctl = {};
+    DECLARE_HYPERCALL_BUFFER(uint32_t, local);
+    int ret = -1;
+
+    if ( num_llc_colors )
+    {
+        size_t bytes = sizeof(uint32_t) * num_llc_colors;
+
+        local = xc_hypercall_buffer_alloc(xch, local, bytes);
+        if ( local == NULL )
+        {
+            PERROR("Could not allocate LLC colors for set_llc_colors");
+            ret = -ENOMEM;
+            goto out;
+        }
+        memcpy(local, llc_colors, bytes);
+        set_xen_guest_handle(domctl.u.set_llc_colors.llc_colors, local);
+    }
+
+    domctl.cmd = XEN_DOMCTL_set_llc_colors;
+    domctl.domain = domid;
+    domctl.u.set_llc_colors.num_llc_colors = num_llc_colors;
+
+    ret = do_domctl(xch, &domctl);
+
+out:
+    xc_hypercall_buffer_free(xch, local);
+
+    return ret;
+}
 /*
  * Local variables:
  * mode: C
diff --git a/tools/libs/light/libxl_create.c b/tools/libs/light/libxl_create.c
index edeadd57ef..e03599ea99 100644
--- a/tools/libs/light/libxl_create.c
+++ b/tools/libs/light/libxl_create.c
@@ -747,6 +747,24 @@  int libxl__domain_make(libxl__gc *gc, libxl_domain_config *d_config,
             /* A new domain now exists */
             *domid = local_domid;
 
+            ret = xc_domain_set_llc_colors(ctx->xch, local_domid,
+                                           b_info->llc_colors,
+                                           b_info->num_llc_colors);
+            if (ret < 0) {
+                if (errno == EOPNOTSUPP) {
+                    if (b_info->num_llc_colors > 0) {
+                        LOGED(ERROR, local_domid,
+                            "LLC coloring not enabled in the hypervisor");
+                        rc = ERROR_FAIL;
+                        goto out;
+                    }
+                } else {
+                    LOGED(ERROR, local_domid, "LLC colors allocation failed");
+                    rc = ERROR_FAIL;
+                    goto out;
+                }
+            }
+
             rc = libxl__is_domid_recent(gc, local_domid, &recent);
             if (rc)
                 goto out;
diff --git a/tools/libs/light/libxl_types.idl b/tools/libs/light/libxl_types.idl
index 4e65e6fda5..bd4b8721ff 100644
--- a/tools/libs/light/libxl_types.idl
+++ b/tools/libs/light/libxl_types.idl
@@ -616,6 +616,7 @@  libxl_domain_build_info = Struct("domain_build_info",[
     ("ioports",          Array(libxl_ioport_range, "num_ioports")),
     ("irqs",             Array(uint32, "num_irqs")),
     ("iomem",            Array(libxl_iomem_range, "num_iomem")),
+    ("llc_colors",       Array(uint32, "num_llc_colors")),
     ("claim_mode",	     libxl_defbool),
     ("event_channels",   uint32),
     ("kernel",           string),
diff --git a/tools/xl/xl_parse.c b/tools/xl/xl_parse.c
index e3a4800f6e..3d85be7dd4 100644
--- a/tools/xl/xl_parse.c
+++ b/tools/xl/xl_parse.c
@@ -1296,7 +1296,7 @@  void parse_config_data(const char *config_source,
     XLU_ConfigList *cpus, *vbds, *nics, *pcis, *cvfbs, *cpuids, *vtpms,
                    *usbctrls, *usbdevs, *p9devs, *vdispls, *pvcallsifs_devs;
     XLU_ConfigList *channels, *ioports, *irqs, *iomem, *viridian, *dtdevs,
-                   *mca_caps, *smbios;
+                   *mca_caps, *smbios, *llc_colors;
     int num_ioports, num_irqs, num_iomem, num_cpus, num_viridian, num_mca_caps;
     int num_smbios;
     int pci_power_mgmt = 0;
@@ -1304,6 +1304,7 @@  void parse_config_data(const char *config_source,
     int pci_permissive = 0;
     int pci_seize = 0;
     int i, e;
+    int num_llc_colors;
     char *kernel_basename;
 
     libxl_domain_create_info *c_info = &d_config->c_info;
@@ -1447,6 +1448,41 @@  void parse_config_data(const char *config_source,
     if (!xlu_cfg_get_long (config, "maxmem", &l, 0))
         b_info->max_memkb = l * 1024;
 
+    if (!xlu_cfg_get_list(config, "llc_colors", &llc_colors, &num_llc_colors, 0)) {
+        int cur_index = 0;
+
+        b_info->num_llc_colors = 0;
+        for (i = 0; i < num_llc_colors; i++) {
+            uint32_t start = 0, end = 0, k;
+
+            buf = xlu_cfg_get_listitem(llc_colors, i);
+            if (!buf) {
+                fprintf(stderr,
+                        "xl: Can't get element %d in LLC color list\n", i);
+                exit(1);
+            }
+
+            if (sscanf(buf, "%" SCNu32 "-%" SCNu32, &start, &end) != 2) {
+                if (sscanf(buf, "%" SCNu32, &start) != 1) {
+                    fprintf(stderr, "xl: Invalid LLC color range: %s\n", buf);
+                    exit(1);
+                }
+                end = start;
+            } else if (start > end) {
+                fprintf(stderr,
+                        "xl: Start LLC color is greater than end: %s\n", buf);
+                exit(1);
+            }
+
+            b_info->num_llc_colors += (end - start) + 1;
+            b_info->llc_colors = (uint32_t *)realloc(b_info->llc_colors,
+                        sizeof(*b_info->llc_colors) * b_info->num_llc_colors);
+
+            for (k = start; k <= end; k++)
+                b_info->llc_colors[cur_index++] = k;
+        }
+    }
+
     if (!xlu_cfg_get_long (config, "vcpus", &l, 0)) {
         vcpus = l;
         if (libxl_cpu_bitmap_alloc(ctx, &b_info->avail_vcpus, l)) {