| Message ID | 20250328200459.483089-10-richard.henderson@linaro.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | single-binary: Restrict scope of TARGET_PAGE_BITS_MIN | expand |
On 3/28/25 13:04, Richard Henderson wrote: > The only place we really need to know the minimum is within > page-vary-target.c. Rename the target/arm TARGET_PAGE_BITS_MIN > to TARGE_PAGE_BITS_LEGACY to emphasize what it really means. > Move the assertions related to minimum page size as well. > s/TARGE_PAGE_BITS_LEGACY/TARGET_PAGE_BITS_LEGACY > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > include/exec/cpu-defs.h | 10 ++-------- > include/exec/poison.h | 1 + > include/exec/target_page.h | 1 - > include/qemu/osdep.h | 6 ++++++ > target/alpha/cpu-param.h | 1 - > target/arm/cpu-param.h | 3 +-- > target/ppc/cpu-param.h | 1 - > accel/tcg/cputlb.c | 1 - > page-vary-target.c | 39 +++++++++++++++++++++++++++++++++++--- > 9 files changed, 46 insertions(+), 17 deletions(-) > > diff --git a/include/exec/cpu-defs.h b/include/exec/cpu-defs.h > index 9f955f53fd..e01acb7c90 100644 > --- a/include/exec/cpu-defs.h > +++ b/include/exec/cpu-defs.h > @@ -34,14 +34,8 @@ > #ifndef TARGET_VIRT_ADDR_SPACE_BITS > # error TARGET_VIRT_ADDR_SPACE_BITS must be defined in cpu-param.h > #endif > -#ifndef TARGET_PAGE_BITS > -# ifdef TARGET_PAGE_BITS_VARY > -# ifndef TARGET_PAGE_BITS_MIN > -# error TARGET_PAGE_BITS_MIN must be defined in cpu-param.h > -# endif > -# else > -# error TARGET_PAGE_BITS must be defined in cpu-param.h > -# endif > +#if !defined(TARGET_PAGE_BITS) && !defined(TARGET_PAGE_BITS_VARY) > +# error TARGET_PAGE_BITS must be defined in cpu-param.h > #endif > > #include "exec/target_long.h" > diff --git a/include/exec/poison.h b/include/exec/poison.h > index 4180a5a489..c4f7ee22bf 100644 > --- a/include/exec/poison.h > +++ b/include/exec/poison.h > @@ -44,6 +44,7 @@ > #pragma GCC poison TARGET_FMT_lu > > #pragma GCC poison TARGET_PHYS_ADDR_SPACE_BITS > +#pragma GCC poison TARGET_PAGE_BITS_LEGACY > > #pragma GCC poison CONFIG_ALPHA_DIS > #pragma GCC poison CONFIG_HPPA_DIS > diff --git a/include/exec/target_page.h b/include/exec/target_page.h > index e4bd7f7767..ca0ebbc8bb 100644 > --- a/include/exec/target_page.h > +++ b/include/exec/target_page.h > @@ -41,7 +41,6 @@ extern const TargetPageBits target_page; > # endif > # define TARGET_PAGE_SIZE (-(int)TARGET_PAGE_MASK) > #else > -# define TARGET_PAGE_BITS_MIN TARGET_PAGE_BITS > # define TARGET_PAGE_SIZE (1 << TARGET_PAGE_BITS) > # define TARGET_PAGE_MASK ((TARGET_PAGE_TYPE)-1 << TARGET_PAGE_BITS) > #endif > diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h > index 4397a90680..321a52d7f0 100644 > --- a/include/qemu/osdep.h > +++ b/include/qemu/osdep.h > @@ -50,6 +50,12 @@ > */ > #pragma GCC poison TARGET_WORDS_BIGENDIAN > > +/* > + * TARGET_PAGE_BITS_MIN was repaced by TARGET_PAGE_BITS_LEGACY > + * for system mode. Prevent it from creeping back in. > + */ s/repaced/replaced > +#pragma GCC poison TARGET_PAGE_BITS_MIN > + > #include "qemu/compiler.h" > > /* Older versions of C++ don't get definitions of various macros from > diff --git a/target/alpha/cpu-param.h b/target/alpha/cpu-param.h > index ff06e41497..63989e71c0 100644 > --- a/target/alpha/cpu-param.h > +++ b/target/alpha/cpu-param.h > @@ -18,7 +18,6 @@ > * a 4k minimum to match x86 host, which can minimize emulation issues. > */ > # define TARGET_PAGE_BITS_VARY > -# define TARGET_PAGE_BITS_MIN 12 > # define TARGET_VIRT_ADDR_SPACE_BITS 63 > #else > # define TARGET_PAGE_BITS 13 > diff --git a/target/arm/cpu-param.h b/target/arm/cpu-param.h > index 896b35bd6d..a7ae42d17d 100644 > --- a/target/arm/cpu-param.h > +++ b/target/arm/cpu-param.h > @@ -24,7 +24,6 @@ > # else > /* Allow user-only to vary page size from 4k */ > # define TARGET_PAGE_BITS_VARY > -# define TARGET_PAGE_BITS_MIN 12 > # endif > # else > # define TARGET_PAGE_BITS 12 > @@ -35,7 +34,7 @@ > * have to support 1K tiny pages. > */ > # define TARGET_PAGE_BITS_VARY > -# define TARGET_PAGE_BITS_MIN 10 > +# define TARGET_PAGE_BITS_LEGACY 10 > #endif /* !CONFIG_USER_ONLY */ > > /* ARM processors have a weak memory model */ > diff --git a/target/ppc/cpu-param.h b/target/ppc/cpu-param.h > index 6c4525fdf3..553ad2f4c6 100644 > --- a/target/ppc/cpu-param.h > +++ b/target/ppc/cpu-param.h > @@ -33,7 +33,6 @@ > #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 > diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c > index 39314e86f3..0de46903dd 100644 > --- a/accel/tcg/cputlb.c > +++ b/accel/tcg/cputlb.c > @@ -49,7 +49,6 @@ > #endif > #include "tcg/tcg-ldst.h" > > -QEMU_BUILD_BUG_ON(TLB_FLAGS_MASK & ((1u < TARGET_PAGE_BITS_MIN) - 1)); > > /* DEBUG defines, enable DEBUG_TLB_LOG to log to the CPU_LOG_MMU target */ > /* #define DEBUG_TLB */ > diff --git a/page-vary-target.c b/page-vary-target.c > index 6251d948cf..d83f9a6a90 100644 > --- a/page-vary-target.c > +++ b/page-vary-target.c > @@ -23,19 +23,45 @@ > #include "exec/page-vary.h" > #include "exec/target_page.h" > > + > +/* > + * For system mode, the minimum comes from the number of bits > + * required for maximum alignment (6) and the number of bits > + * required for TLB_FLAGS_MASK (3). > + * > + * For user mode, TARGET_PAGE_BITS_VARY is a hack to allow the target > + * page size to match the host page size. Mostly, this reduces the > + * ordinary target page size to run on a host with 4KiB pages (i.e. x86). > + * There is no true minimum required by the implementation, but keep the > + * same minimum as for system mode for sanity. > + * See linux-user/mmap.c, mmap_h_lt_g and mmap_h_gt_g. > + */ > +#define TARGET_PAGE_BITS__MIN 9 > + > +#ifndef TARGET_PAGE_BITS_VARY > +QEMU_BUILD_BUG_ON(TARGET_PAGE_BITS < TARGET_PAGE_BITS__MIN); > +#endif > + > +#ifndef CONFIG_USER_ONLY > +#include "exec/tlb-flags.h" > + > +QEMU_BUILD_BUG_ON(TLB_FLAGS_MASK & ((1u < TARGET_PAGE_BITS__MIN) - 1)); > + > int migration_legacy_page_bits(void) > { > #ifdef TARGET_PAGE_BITS_VARY > - return TARGET_PAGE_BITS_MIN; > + QEMU_BUILD_BUG_ON(TARGET_PAGE_BITS_LEGACY < TARGET_PAGE_BITS__MIN); > + return TARGET_PAGE_BITS_LEGACY; > #else > return TARGET_PAGE_BITS; > #endif > } > +#endif > > bool set_preferred_target_page_bits(int bits) > { > + assert(bits >= TARGET_PAGE_BITS__MIN); > #ifdef TARGET_PAGE_BITS_VARY > - assert(bits >= TARGET_PAGE_BITS_MIN); > return set_preferred_target_page_bits_common(bits); > #else > return true; > @@ -44,5 +70,12 @@ bool set_preferred_target_page_bits(int bits) > > void finalize_target_page_bits(void) > { > - finalize_target_page_bits_common(TARGET_PAGE_BITS_MIN); > +#ifndef TARGET_PAGE_BITS_VARY > + finalize_target_page_bits_common(TARGET_PAGE_BITS); > +#elif defined(CONFIG_USER_ONLY) > + assert(target_page.bits != 0); > + finalize_target_page_bits_common(target_page.bits); > +#else > + finalize_target_page_bits_common(TARGET_PAGE_BITS_LEGACY); > +#endif > } Great! Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org> Any chance we would rename TARGET_PAGE_BITS__MIN? (MIN_ALL? ALL_MIN? ARCH_MIN? any other idea) I know it's restricted to this file only, but the __ is surprising.
On 3/28/25 15:38, Pierrick Bouvier wrote: > Any chance we would rename TARGET_PAGE_BITS__MIN? (MIN_ALL? ALL_MIN? ARCH_MIN? any other > idea) > I know it's restricted to this file only, but the __ is surprising. I could drop the poisoning. Since there have only ever been two targets using TARGET_PAGE_BITS_VARY, it's unlikely creep back in unawares. r~
diff --git a/include/exec/cpu-defs.h b/include/exec/cpu-defs.h index 9f955f53fd..e01acb7c90 100644 --- a/include/exec/cpu-defs.h +++ b/include/exec/cpu-defs.h @@ -34,14 +34,8 @@ #ifndef TARGET_VIRT_ADDR_SPACE_BITS # error TARGET_VIRT_ADDR_SPACE_BITS must be defined in cpu-param.h #endif -#ifndef TARGET_PAGE_BITS -# ifdef TARGET_PAGE_BITS_VARY -# ifndef TARGET_PAGE_BITS_MIN -# error TARGET_PAGE_BITS_MIN must be defined in cpu-param.h -# endif -# else -# error TARGET_PAGE_BITS must be defined in cpu-param.h -# endif +#if !defined(TARGET_PAGE_BITS) && !defined(TARGET_PAGE_BITS_VARY) +# error TARGET_PAGE_BITS must be defined in cpu-param.h #endif #include "exec/target_long.h" diff --git a/include/exec/poison.h b/include/exec/poison.h index 4180a5a489..c4f7ee22bf 100644 --- a/include/exec/poison.h +++ b/include/exec/poison.h @@ -44,6 +44,7 @@ #pragma GCC poison TARGET_FMT_lu #pragma GCC poison TARGET_PHYS_ADDR_SPACE_BITS +#pragma GCC poison TARGET_PAGE_BITS_LEGACY #pragma GCC poison CONFIG_ALPHA_DIS #pragma GCC poison CONFIG_HPPA_DIS diff --git a/include/exec/target_page.h b/include/exec/target_page.h index e4bd7f7767..ca0ebbc8bb 100644 --- a/include/exec/target_page.h +++ b/include/exec/target_page.h @@ -41,7 +41,6 @@ extern const TargetPageBits target_page; # endif # define TARGET_PAGE_SIZE (-(int)TARGET_PAGE_MASK) #else -# define TARGET_PAGE_BITS_MIN TARGET_PAGE_BITS # define TARGET_PAGE_SIZE (1 << TARGET_PAGE_BITS) # define TARGET_PAGE_MASK ((TARGET_PAGE_TYPE)-1 << TARGET_PAGE_BITS) #endif diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index 4397a90680..321a52d7f0 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -50,6 +50,12 @@ */ #pragma GCC poison TARGET_WORDS_BIGENDIAN +/* + * TARGET_PAGE_BITS_MIN was repaced by TARGET_PAGE_BITS_LEGACY + * for system mode. Prevent it from creeping back in. + */ +#pragma GCC poison TARGET_PAGE_BITS_MIN + #include "qemu/compiler.h" /* Older versions of C++ don't get definitions of various macros from diff --git a/target/alpha/cpu-param.h b/target/alpha/cpu-param.h index ff06e41497..63989e71c0 100644 --- a/target/alpha/cpu-param.h +++ b/target/alpha/cpu-param.h @@ -18,7 +18,6 @@ * a 4k minimum to match x86 host, which can minimize emulation issues. */ # define TARGET_PAGE_BITS_VARY -# define TARGET_PAGE_BITS_MIN 12 # define TARGET_VIRT_ADDR_SPACE_BITS 63 #else # define TARGET_PAGE_BITS 13 diff --git a/target/arm/cpu-param.h b/target/arm/cpu-param.h index 896b35bd6d..a7ae42d17d 100644 --- a/target/arm/cpu-param.h +++ b/target/arm/cpu-param.h @@ -24,7 +24,6 @@ # else /* Allow user-only to vary page size from 4k */ # define TARGET_PAGE_BITS_VARY -# define TARGET_PAGE_BITS_MIN 12 # endif # else # define TARGET_PAGE_BITS 12 @@ -35,7 +34,7 @@ * have to support 1K tiny pages. */ # define TARGET_PAGE_BITS_VARY -# define TARGET_PAGE_BITS_MIN 10 +# define TARGET_PAGE_BITS_LEGACY 10 #endif /* !CONFIG_USER_ONLY */ /* ARM processors have a weak memory model */ diff --git a/target/ppc/cpu-param.h b/target/ppc/cpu-param.h index 6c4525fdf3..553ad2f4c6 100644 --- a/target/ppc/cpu-param.h +++ b/target/ppc/cpu-param.h @@ -33,7 +33,6 @@ #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 diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c index 39314e86f3..0de46903dd 100644 --- a/accel/tcg/cputlb.c +++ b/accel/tcg/cputlb.c @@ -49,7 +49,6 @@ #endif #include "tcg/tcg-ldst.h" -QEMU_BUILD_BUG_ON(TLB_FLAGS_MASK & ((1u < TARGET_PAGE_BITS_MIN) - 1)); /* DEBUG defines, enable DEBUG_TLB_LOG to log to the CPU_LOG_MMU target */ /* #define DEBUG_TLB */ diff --git a/page-vary-target.c b/page-vary-target.c index 6251d948cf..d83f9a6a90 100644 --- a/page-vary-target.c +++ b/page-vary-target.c @@ -23,19 +23,45 @@ #include "exec/page-vary.h" #include "exec/target_page.h" + +/* + * For system mode, the minimum comes from the number of bits + * required for maximum alignment (6) and the number of bits + * required for TLB_FLAGS_MASK (3). + * + * For user mode, TARGET_PAGE_BITS_VARY is a hack to allow the target + * page size to match the host page size. Mostly, this reduces the + * ordinary target page size to run on a host with 4KiB pages (i.e. x86). + * There is no true minimum required by the implementation, but keep the + * same minimum as for system mode for sanity. + * See linux-user/mmap.c, mmap_h_lt_g and mmap_h_gt_g. + */ +#define TARGET_PAGE_BITS__MIN 9 + +#ifndef TARGET_PAGE_BITS_VARY +QEMU_BUILD_BUG_ON(TARGET_PAGE_BITS < TARGET_PAGE_BITS__MIN); +#endif + +#ifndef CONFIG_USER_ONLY +#include "exec/tlb-flags.h" + +QEMU_BUILD_BUG_ON(TLB_FLAGS_MASK & ((1u < TARGET_PAGE_BITS__MIN) - 1)); + int migration_legacy_page_bits(void) { #ifdef TARGET_PAGE_BITS_VARY - return TARGET_PAGE_BITS_MIN; + QEMU_BUILD_BUG_ON(TARGET_PAGE_BITS_LEGACY < TARGET_PAGE_BITS__MIN); + return TARGET_PAGE_BITS_LEGACY; #else return TARGET_PAGE_BITS; #endif } +#endif bool set_preferred_target_page_bits(int bits) { + assert(bits >= TARGET_PAGE_BITS__MIN); #ifdef TARGET_PAGE_BITS_VARY - assert(bits >= TARGET_PAGE_BITS_MIN); return set_preferred_target_page_bits_common(bits); #else return true; @@ -44,5 +70,12 @@ bool set_preferred_target_page_bits(int bits) void finalize_target_page_bits(void) { - finalize_target_page_bits_common(TARGET_PAGE_BITS_MIN); +#ifndef TARGET_PAGE_BITS_VARY + finalize_target_page_bits_common(TARGET_PAGE_BITS); +#elif defined(CONFIG_USER_ONLY) + assert(target_page.bits != 0); + finalize_target_page_bits_common(target_page.bits); +#else + finalize_target_page_bits_common(TARGET_PAGE_BITS_LEGACY); +#endif }
The only place we really need to know the minimum is within page-vary-target.c. Rename the target/arm TARGET_PAGE_BITS_MIN to TARGE_PAGE_BITS_LEGACY to emphasize what it really means. Move the assertions related to minimum page size as well. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- include/exec/cpu-defs.h | 10 ++-------- include/exec/poison.h | 1 + include/exec/target_page.h | 1 - include/qemu/osdep.h | 6 ++++++ target/alpha/cpu-param.h | 1 - target/arm/cpu-param.h | 3 +-- target/ppc/cpu-param.h | 1 - accel/tcg/cputlb.c | 1 - page-vary-target.c | 39 +++++++++++++++++++++++++++++++++++--- 9 files changed, 46 insertions(+), 17 deletions(-)