[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH v2 04/12] util: add qemu_get_host_physmem utility function
From: |
Alex Bennée |
Subject: |
[PATCH v2 04/12] util: add qemu_get_host_physmem utility function |
Date: |
Wed, 22 Jul 2020 07:28:54 +0100 |
This will be used in a future patch. For POSIX systems _SC_PHYS_PAGES
isn't standardised but at least appears in the man pages for
Open/FreeBSD. The result is advisory so any users of it shouldn't just
fail if we can't work it out.
The win32 stub currently returns 0 until someone with a Windows system
can develop and test a patch.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Cc: BALATON Zoltan <balaton@eik.bme.hu>
Cc: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Message-Id: <20200717105139.25293-5-alex.bennee@linaro.org>
---
v2
- fix agnostic typo
- saturate to SIZE_MAX rather than overflow
---
include/qemu/osdep.h | 12 ++++++++++++
util/oslib-posix.c | 15 +++++++++++++++
util/oslib-win32.c | 6 ++++++
3 files changed, 33 insertions(+)
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index 4841b5c6b5f..e44547fb33e 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -665,4 +665,16 @@ static inline void qemu_reset_optind(void)
*/
char *qemu_get_host_name(Error **errp);
+/**
+ * qemu_get_host_physmem:
+ *
+ * Operating system agnostic way of querying host memory.
+ *
+ * Returns amount of physical memory on the system. This is purely
+ * advisery and may return 0 if we can't work it out. At the other
+ * end we saturate to SIZE_MAX if you are lucky enough to have that
+ * much memory.
+ */
+size_t qemu_get_host_physmem(void);
+
#endif
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index d9236746248..ad8001a4ad8 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -841,3 +841,18 @@ char *qemu_get_host_name(Error **errp)
return g_steal_pointer(&hostname);
}
+
+size_t qemu_get_host_physmem(void)
+{
+#ifdef _SC_PHYS_PAGES
+ long pages = sysconf(_SC_PHYS_PAGES);
+ if (pages > 0) {
+ if (pages > SIZE_MAX / qemu_real_host_page_size) {
+ return SIZE_MAX;
+ } else {
+ return pages * qemu_real_host_page_size;
+ }
+ }
+#endif
+ return 0;
+}
diff --git a/util/oslib-win32.c b/util/oslib-win32.c
index 7eedbe5859a..31030463cc9 100644
--- a/util/oslib-win32.c
+++ b/util/oslib-win32.c
@@ -828,3 +828,9 @@ char *qemu_get_host_name(Error **errp)
return g_utf16_to_utf8(tmp, size, NULL, NULL, NULL);
}
+
+size_t qemu_get_host_physmem(void)
+{
+ /* currently unimplemented */
+ return 0;
+}
--
2.20.1
- [PATCH v2 00/12] candidate fixes for 5.1-rc1 (testing, semihosting, OOM tcg, x86 fpu), Alex Bennée, 2020/07/22
- [PATCH v2 01/12] shippable: add one more qemu to registry url, Alex Bennée, 2020/07/22
- [PATCH v2 02/12] semihosting: defer connect_chardevs a little more to use serialx, Alex Bennée, 2020/07/22
- [PATCH v2 04/12] util: add qemu_get_host_physmem utility function,
Alex Bennée <=
- [PATCH v2 03/12] semihosting: don't send the trailing '\0', Alex Bennée, 2020/07/22
- [PATCH v2 06/12] accel/tcg: better handle memory constrained systems, Alex Bennée, 2020/07/22
- Re: [PATCH v2 06/12] accel/tcg: better handle memory constrained systems, Richard Henderson, 2020/07/22
- Re: [PATCH v2 06/12] accel/tcg: better handle memory constrained systems, Alex Bennée, 2020/07/22
- Re: [PATCH v2 06/12] accel/tcg: better handle memory constrained systems, Daniel P . Berrangé, 2020/07/22
- Re: [PATCH v2 06/12] accel/tcg: better handle memory constrained systems, Richard Henderson, 2020/07/22
- Re: [PATCH v2 06/12] accel/tcg: better handle memory constrained systems, Daniel P . Berrangé, 2020/07/23
- Re: [PATCH v2 06/12] accel/tcg: better handle memory constrained systems, Alex Bennée, 2020/07/23
- Re: [PATCH v2 06/12] accel/tcg: better handle memory constrained systems, Daniel P . Berrangé, 2020/07/23