* [PATCH 0/2] exec: Ensure variable page size is only used with TARGET_PAGE_BITS_VARY
@ 2020-11-04 9:35 Philippe Mathieu-Daudé
2020-11-04 9:35 ` [PATCH 1/2] MAINTAINERS: Cover exec-vary.c (variable page size) Philippe Mathieu-Daudé
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-11-04 9:35 UTC (permalink / raw)
To: qemu-devel
Cc: Paolo Bonzini, Richard Henderson, Philippe Mathieu-Daudé,
Richard Henderson
Simple patch while trying to figure out Fuloong-2E 16KB page size.
Better safe than sorry =)
Philippe Mathieu-Daudé (2):
MAINTAINERS: Cover exec-vary.c (variable page size)
exec: Ensure variable page size is only used with
TARGET_PAGE_BITS_VARY
include/qemu-common.h | 4 +++-
exec-vary.c | 4 +++-
MAINTAINERS | 1 +
3 files changed, 7 insertions(+), 2 deletions(-)
--
2.26.2
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH 1/2] MAINTAINERS: Cover exec-vary.c (variable page size)
2020-11-04 9:35 [PATCH 0/2] exec: Ensure variable page size is only used with TARGET_PAGE_BITS_VARY Philippe Mathieu-Daudé
@ 2020-11-04 9:35 ` Philippe Mathieu-Daudé
2020-11-04 9:35 ` [PATCH 2/2] exec: Ensure variable page size is only used with TARGET_PAGE_BITS_VARY Philippe Mathieu-Daudé
2020-11-23 12:28 ` [PATCH-for-6.0 0/2] " Philippe Mathieu-Daudé
2 siblings, 0 replies; 5+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-11-04 9:35 UTC (permalink / raw)
To: qemu-devel
Cc: Paolo Bonzini, Richard Henderson, Philippe Mathieu-Daudé,
Richard Henderson
Add exec-vary.c to the 'Overall TCG CPUs' section.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
MAINTAINERS | 1 +
1 file changed, 1 insertion(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index dd16606bcdc..466898d3dbd 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -117,6 +117,7 @@ R: Paolo Bonzini <pbonzini@redhat.com>
S: Maintained
F: softmmu/cpus.c
F: cpus-common.c
+F: exec-vary.c
F: accel/tcg/
F: accel/stubs/tcg-stub.c
F: scripts/decodetree.py
--
2.26.2
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 2/2] exec: Ensure variable page size is only used with TARGET_PAGE_BITS_VARY
2020-11-04 9:35 [PATCH 0/2] exec: Ensure variable page size is only used with TARGET_PAGE_BITS_VARY Philippe Mathieu-Daudé
2020-11-04 9:35 ` [PATCH 1/2] MAINTAINERS: Cover exec-vary.c (variable page size) Philippe Mathieu-Daudé
@ 2020-11-04 9:35 ` Philippe Mathieu-Daudé
2020-11-24 16:12 ` Richard Henderson
2020-11-23 12:28 ` [PATCH-for-6.0 0/2] " Philippe Mathieu-Daudé
2 siblings, 1 reply; 5+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-11-04 9:35 UTC (permalink / raw)
To: qemu-devel
Cc: Paolo Bonzini, Richard Henderson, Philippe Mathieu-Daudé,
Richard Henderson
If TARGET_PAGE_BITS_VARY is not supported, machines should not
intent to modify the target page size.
As set_preferred_target_page_bits() is supposed to return 'false'
on failure (documented in "qemu-common.h"), return false to
indicate failure if this ever happens.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
include/qemu-common.h | 4 +++-
exec-vary.c | 4 +++-
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/include/qemu-common.h b/include/qemu-common.h
index fda7dc6ca77..3ea616d4567 100644
--- a/include/qemu-common.h
+++ b/include/qemu-common.h
@@ -70,7 +70,9 @@ void cpu_exec_step_atomic(CPUState *cpu);
* size may be smaller than any given CPU's preference).
* Returns true on success, false on failure (which can only happen
* if this is called after the system has already finalized its
- * choice of page size and the requested page size is smaller than that).
+ * choice of page size and the requested page size is smaller than
+ * that). Only target supporting variable page size should set a
+ * preferred target page size.
*/
bool set_preferred_target_page_bits(int bits);
diff --git a/exec-vary.c b/exec-vary.c
index ff905f2a8fb..4b0b7f193af 100644
--- a/exec-vary.c
+++ b/exec-vary.c
@@ -86,8 +86,10 @@ bool set_preferred_target_page_bits(int bits)
}
init_target_page.bits = bits;
}
-#endif
return true;
+#else
+ return false;
+#endif
}
void finalize_target_page_bits(void)
--
2.26.2
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH-for-6.0 0/2] exec: Ensure variable page size is only used with TARGET_PAGE_BITS_VARY
2020-11-04 9:35 [PATCH 0/2] exec: Ensure variable page size is only used with TARGET_PAGE_BITS_VARY Philippe Mathieu-Daudé
2020-11-04 9:35 ` [PATCH 1/2] MAINTAINERS: Cover exec-vary.c (variable page size) Philippe Mathieu-Daudé
2020-11-04 9:35 ` [PATCH 2/2] exec: Ensure variable page size is only used with TARGET_PAGE_BITS_VARY Philippe Mathieu-Daudé
@ 2020-11-23 12:28 ` Philippe Mathieu-Daudé
2 siblings, 0 replies; 5+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-11-23 12:28 UTC (permalink / raw)
To: qemu-devel; +Cc: Paolo Bonzini, Richard Henderson
ping?
On 11/4/20 10:35 AM, Philippe Mathieu-Daudé wrote:
> Simple patch while trying to figure out Fuloong-2E 16KB page size.
> Better safe than sorry =)
>
> Philippe Mathieu-Daudé (2):
> MAINTAINERS: Cover exec-vary.c (variable page size)
> exec: Ensure variable page size is only used with
> TARGET_PAGE_BITS_VARY
>
> include/qemu-common.h | 4 +++-
> exec-vary.c | 4 +++-
> MAINTAINERS | 1 +
> 3 files changed, 7 insertions(+), 2 deletions(-)
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 2/2] exec: Ensure variable page size is only used with TARGET_PAGE_BITS_VARY
2020-11-04 9:35 ` [PATCH 2/2] exec: Ensure variable page size is only used with TARGET_PAGE_BITS_VARY Philippe Mathieu-Daudé
@ 2020-11-24 16:12 ` Richard Henderson
0 siblings, 0 replies; 5+ messages in thread
From: Richard Henderson @ 2020-11-24 16:12 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, qemu-devel; +Cc: Paolo Bonzini, Richard Henderson
On 11/4/20 1:35 AM, Philippe Mathieu-Daudé wrote:
> If TARGET_PAGE_BITS_VARY is not supported, machines should not
> intent to modify the target page size.
> As set_preferred_target_page_bits() is supposed to return 'false'
> on failure (documented in "qemu-common.h"), return false to
> indicate failure if this ever happens.
>
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
> include/qemu-common.h | 4 +++-
> exec-vary.c | 4 +++-
> 2 files changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/include/qemu-common.h b/include/qemu-common.h
> index fda7dc6ca77..3ea616d4567 100644
> --- a/include/qemu-common.h
> +++ b/include/qemu-common.h
> @@ -70,7 +70,9 @@ void cpu_exec_step_atomic(CPUState *cpu);
> * size may be smaller than any given CPU's preference).
> * Returns true on success, false on failure (which can only happen
> * if this is called after the system has already finalized its
> - * choice of page size and the requested page size is smaller than that).
> + * choice of page size and the requested page size is smaller than
> + * that). Only target supporting variable page size should set a
> + * preferred target page size.
> */
> bool set_preferred_target_page_bits(int bits);
>
> diff --git a/exec-vary.c b/exec-vary.c
> index ff905f2a8fb..4b0b7f193af 100644
> --- a/exec-vary.c
> +++ b/exec-vary.c
> @@ -86,8 +86,10 @@ bool set_preferred_target_page_bits(int bits)
> }
> init_target_page.bits = bits;
> }
> -#endif
> return true;
> +#else
> + return false;
> +#endif
I guess the only generic caller is the one in softmmu/vl.c, which is protected
by machine_class->minimum_page_bits != 0. So this affects exactly one machine
outside arm -- fuloong2e.
Certainly we should not allow an impossible setting. I wonder if it is worth
doing return bits == TARGET_PAGE_BITS?
Either way,
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
r~
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2020-11-24 16:14 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-11-04 9:35 [PATCH 0/2] exec: Ensure variable page size is only used with TARGET_PAGE_BITS_VARY Philippe Mathieu-Daudé
2020-11-04 9:35 ` [PATCH 1/2] MAINTAINERS: Cover exec-vary.c (variable page size) Philippe Mathieu-Daudé
2020-11-04 9:35 ` [PATCH 2/2] exec: Ensure variable page size is only used with TARGET_PAGE_BITS_VARY Philippe Mathieu-Daudé
2020-11-24 16:12 ` Richard Henderson
2020-11-23 12:28 ` [PATCH-for-6.0 0/2] " Philippe Mathieu-Daudé
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.