Introduce a new tool to fetch Intel CPU temperatures through the
Intel DTS interface using XENPF_resource_op hypercall.
Signed-off-by: Teddy Astie <teddy.astie@vates.tech>
---
tools/misc/.gitignore | 1 +
tools/misc/Makefile | 4 ++
tools/misc/xen-inteltemp.c | 98 ++++++++++++++++++++++++++++++++++++++
3 files changed, 103 insertions(+)
create mode 100644 tools/misc/xen-inteltemp.c
diff --git a/tools/misc/.gitignore b/tools/misc/.gitignore
index 28af46280f..65048eb901 100644
--- a/tools/misc/.gitignore
+++ b/tools/misc/.gitignore
@@ -5,6 +5,7 @@ xen-diag
xen-hptool
xen-hvmcrash
xen-hvmctx
+xen-inteltemp
xen-livepatch
xen-lowmemd
xen-mceinj
diff --git a/tools/misc/Makefile b/tools/misc/Makefile
index c26e544e83..6498b47ec0 100644
--- a/tools/misc/Makefile
+++ b/tools/misc/Makefile
@@ -25,6 +25,7 @@ INSTALL_SBIN-$(CONFIG_X86) += xen-memshare
INSTALL_SBIN-$(CONFIG_X86) += xen-mfndump
INSTALL_SBIN-$(CONFIG_X86) += xen-ucode
INSTALL_SBIN-$(CONFIG_X86) += xen-vmtrace
+INSTALL_SBIN-$(CONFIG_X86) += xen-inteltemp
INSTALL_SBIN += xencov
INSTALL_SBIN += xenhypfs
INSTALL_SBIN += xenlockprof
@@ -89,6 +90,9 @@ xen-memshare: xen-memshare.o
xen-vmtrace: xen-vmtrace.o
$(CC) $(LDFLAGS) -o $@ $< $(LDLIBS_libxenctrl) $(LDLIBS_libxenforeignmemory) $(APPEND_LDFLAGS)
+xen-inteltemp: xen-inteltemp.o
+ $(CC) $(LDFLAGS) -o $@ $< $(LDLIBS_libxenctrl) $(APPEND_LDFLAGS)
+
xen-mceinj: xen-mceinj.o
$(CC) $(LDFLAGS) -o $@ $< $(LDLIBS_libxenctrl) $(LDLIBS_libxenguest) $(LDLIBS_libxenstore) $(APPEND_LDFLAGS)
diff --git a/tools/misc/xen-inteltemp.c b/tools/misc/xen-inteltemp.c
new file mode 100644
index 0000000000..624c74ca7f
--- /dev/null
+++ b/tools/misc/xen-inteltemp.c
@@ -0,0 +1,98 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * xen-inteltemp.c
+ *
+ * Get the CPU temperature of Intel processors.
+ *
+ * Copyright 2025 Teddy Astie <teddy.astie@vates.tech>
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <xenctrl.h>
+
+#define MSR_IA32_THERM_STATUS 0x0000019c
+#define MSR_IA32_TEMPERATURE_TARGET 0x000001a2
+#define MSR_IA32_PACKAGE_THERM_STATUS 0x000001b1
+
+int fetch_dts_temp(xc_interface *xch, uint32_t cpu, bool package, int *temp)
+{
+ xc_resource_entry_t entries[2] = {
+ (xc_resource_entry_t){
+ .idx = package ? MSR_IA32_PACKAGE_THERM_STATUS : MSR_IA32_THERM_STATUS
+ },
+ (xc_resource_entry_t){ .idx = MSR_IA32_TEMPERATURE_TARGET },
+ };
+ struct xc_resource_op ops = {
+ .cpu = cpu,
+ .entries = entries,
+ .nr_entries = 2,
+ };
+ int tjmax;
+
+ int ret = xc_resource_op(xch, 1, &ops);
+
+ if ( ret <= 0 )
+ /* This CPU isn't online or can't query this MSR */
+ return ret ?: -EOPNOTSUPP;
+
+ if ( ret == 2 )
+ tjmax = (entries[1].val >> 16) & 0xff;
+ else
+ {
+ /*
+ * The CPU doesn't support MSR_IA32_TEMPERATURE_TARGET, we assume it's 100 which
+ * is correct aside a few selected Atom CPUs. Check coretemp source code for more
+ * information.
+ */
+ fprintf(stderr, "CPU%d doesn't support MSR_IA32_TEMPERATURE_TARGET, assume "
+ "tjmax=100°C, readings may be incorrect\n", cpu);
+ tjmax = 100;
+ }
+
+ *temp = tjmax - ((entries[0].val >> 16) & 0xff);
+ return 0;
+}
+
+int main(void)
+{
+ int rc = 0, temp, cpu, socket;
+ bool has_data = false;
+ xc_interface *xch = xc_interface_open(0, 0, 0);
+ xc_physinfo_t info;
+
+ if ( (rc = xc_physinfo(xch, &info)) < 0 )
+ {
+ perror("Getting physinfo failed");
+ return rc;
+ }
+
+ /* Per socket measurement */
+ for ( socket = 0, cpu = 0;
+ cpu < (info.max_cpu_id + 1);
+ socket++, cpu += info.cores_per_socket * info.threads_per_core )
+ {
+ if ( !fetch_dts_temp(xch, cpu, true, &temp) )
+ {
+ has_data = true;
+ printf("Package%d: %d°C\n", socket, temp);
+ }
+ }
+
+ printf("\n");
+
+ for ( cpu = 0; cpu < (info.max_cpu_id + 1); cpu += info.threads_per_core )
+ {
+ if ( fetch_dts_temp(xch, cpu, false, &temp) )
+ continue;
+
+ has_data = true;
+ printf("CPU%d: %d°C\n", cpu, temp);
+ }
+
+ if ( !has_data )
+ printf("No data\n");
+
+ xc_interface_close(xch);
+ return 0;
+}
\ No newline at end of file
--
2.51.1
--
Teddy Astie | Vates XCP-ng Developer
XCP-ng & Xen Orchestra - Vates solutions
web: https://vates.techOn 27.10.2025 18:26, Teddy Astie wrote:
> Introduce a new tool to fetch Intel CPU temperatures through the
> Intel DTS interface using XENPF_resource_op hypercall.
>
> Signed-off-by: Teddy Astie <teddy.astie@vates.tech>
> ---
> tools/misc/.gitignore | 1 +
> tools/misc/Makefile | 4 ++
> tools/misc/xen-inteltemp.c | 98 ++++++++++++++++++++++++++++++++++++++
> 3 files changed, 103 insertions(+)
> create mode 100644 tools/misc/xen-inteltemp.c
Instead of introducing a new tool, might this not fit in xenpm?
> --- /dev/null
> +++ b/tools/misc/xen-inteltemp.c
> @@ -0,0 +1,98 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * xen-inteltemp.c
> + *
> + * Get the CPU temperature of Intel processors.
> + *
> + * Copyright 2025 Teddy Astie <teddy.astie@vates.tech>
> + */
> +
> +#include <stdio.h>
> +#include <errno.h>
> +#include <xenctrl.h>
> +
> +#define MSR_IA32_THERM_STATUS 0x0000019c
> +#define MSR_IA32_TEMPERATURE_TARGET 0x000001a2
> +#define MSR_IA32_PACKAGE_THERM_STATUS 0x000001b1
> +
> +int fetch_dts_temp(xc_interface *xch, uint32_t cpu, bool package, int *temp)
> +{
> + xc_resource_entry_t entries[2] = {
> + (xc_resource_entry_t){
> + .idx = package ? MSR_IA32_PACKAGE_THERM_STATUS : MSR_IA32_THERM_STATUS
> + },
> + (xc_resource_entry_t){ .idx = MSR_IA32_TEMPERATURE_TARGET },
> + };
> + struct xc_resource_op ops = {
> + .cpu = cpu,
> + .entries = entries,
> + .nr_entries = 2,
> + };
> + int tjmax;
> +
> + int ret = xc_resource_op(xch, 1, &ops);
> +
> + if ( ret <= 0 )
> + /* This CPU isn't online or can't query this MSR */
> + return ret ?: -EOPNOTSUPP;
> +
> + if ( ret == 2 )
> + tjmax = (entries[1].val >> 16) & 0xff;
> + else
> + {
> + /*
> + * The CPU doesn't support MSR_IA32_TEMPERATURE_TARGET, we assume it's 100 which
> + * is correct aside a few selected Atom CPUs. Check coretemp source code for more
> + * information.
> + */
> + fprintf(stderr, "CPU%d doesn't support MSR_IA32_TEMPERATURE_TARGET, assume "
> + "tjmax=100°C, readings may be incorrect\n", cpu);
> + tjmax = 100;
> + }
> +
> + *temp = tjmax - ((entries[0].val >> 16) & 0xff);
> + return 0;
> +}
> +
> +int main(void)
> +{
> + int rc = 0, temp, cpu, socket;
> + bool has_data = false;
> + xc_interface *xch = xc_interface_open(0, 0, 0);
> + xc_physinfo_t info;
> +
> + if ( (rc = xc_physinfo(xch, &info)) < 0 )
> + {
> + perror("Getting physinfo failed");
> + return rc;
> + }
> +
> + /* Per socket measurement */
> + for ( socket = 0, cpu = 0;
> + cpu < (info.max_cpu_id + 1);
> + socket++, cpu += info.cores_per_socket * info.threads_per_core )
> + {
> + if ( !fetch_dts_temp(xch, cpu, true, &temp) )
> + {
> + has_data = true;
> + printf("Package%d: %d°C\n", socket, temp);
> + }
> + }
> +
> + printf("\n");
> +
> + for ( cpu = 0; cpu < (info.max_cpu_id + 1); cpu += info.threads_per_core )
> + {
> + if ( fetch_dts_temp(xch, cpu, false, &temp) )
> + continue;
> +
> + has_data = true;
> + printf("CPU%d: %d°C\n", cpu, temp);
> + }
> +
> + if ( !has_data )
> + printf("No data\n");
> +
> + xc_interface_close(xch);
> + return 0;
> +}
> \ No newline at end of file
Please never introduce files without trailing newline.
Jan
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