[v3] linux-user: Improve host and guest page size handling

[PATCH v3 32/33] target/ppc: Enable TARGET_PAGE_BITS_VARY for user-only

Richard Henderson posted 33 patches 10 months, 4 weeks ago

Diff against v2 v4
Download mbox

Maintainers: Richard Henderson <richard.henderson@linaro.org>, Paolo Bonzini <pbonzini@redhat.com>, Riku Voipio <riku.voipio@iki.fi>, Warner Losh <imp@bsdimp.com>, Kyle Evans <kevans@freebsd.org>, Stefan Berger <stefanb@linux.vnet.ibm.com>, Eduardo Habkost <eduardo@habkost.net>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Yanan Wang <wangyanan55@huawei.com>, Laurent Vivier <laurent@vivier.eu>, Peter Xu <peterx@redhat.com>, Fabiano Rosas <farosas@suse.de>, David Hildenbrand <david@redhat.com>, Peter Maydell <peter.maydell@linaro.org>, Nicholas Piggin <npiggin@gmail.com>, Daniel Henrique Barboza <danielhb413@gmail.com>, "Cédric Le Goater" <clg@kaod.org>, "Alex Bennée" <alex.bennee@linaro.org>, Yoshinori Sato <ysato@users.sourceforge.jp>

There is a newer version of this series

Expand all Fold all

[PATCH v3 32/33] target/ppc: Enable TARGET_PAGE_BITS_VARY for user-only

Posted by Richard Henderson 10 months, 4 weeks ago

Since ppc binaries are generally built for multiple
page sizes, it is trivial to allow the page size to vary.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/ppc/cpu-param.h | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/target/ppc/cpu-param.h b/target/ppc/cpu-param.h
index 0a0416e0a8..b7ad52de03 100644
--- a/target/ppc/cpu-param.h
+++ b/target/ppc/cpu-param.h
@@ -31,6 +31,13 @@
 # define TARGET_PHYS_ADDR_SPACE_BITS 36
 # define TARGET_VIRT_ADDR_SPACE_BITS 32
 #endif
-#define TARGET_PAGE_BITS 12
+
+#ifdef CONFIG_USER_ONLY
+/* Allow user-only to vary page size from 4k */
+# define TARGET_PAGE_BITS_VARY
+# define TARGET_PAGE_BITS_MIN 12
+#else
+# define TARGET_PAGE_BITS 12
+#endif
 
 #endif
-- 
2.34.1

Re: [PATCH v3 32/33] target/ppc: Enable TARGET_PAGE_BITS_VARY for user-only

Posted by Ilya Leoshkevich 10 months ago

On Tue, Jan 02, 2024 at 12:58:07PM +1100, Richard Henderson wrote:
> Since ppc binaries are generally built for multiple
> page sizes, it is trivial to allow the page size to vary.
> 
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/ppc/cpu-param.h | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)

It would be great if it were possible to choose the page size from the
command line for linux-user. I was recently looking into comparing
traces from ppc64le-linux-user and real hardware, and mismatching page
size was one of the things getting in the way. Of course,

--- a/target/ppc/cpu-param.h
+++ b/target/ppc/cpu-param.h
@@ -31,6 +31,10 @@
 # define TARGET_PHYS_ADDR_SPACE_BITS 36
 # define TARGET_VIRT_ADDR_SPACE_BITS 32
 #endif
+#if defined(TARGET_PPC64) && defined(__linux__) && defined(CONFIG_USER_ONLY)
+#define TARGET_PAGE_BITS 16
+#else
 #define TARGET_PAGE_BITS 12
+#endif

worked, but an official support for this would be even better.

Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>