| Message ID | 20230216134911.6803-2-pierrick.bouvier@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Adds support for running QEMU natively on windows-arm64 | expand |
On 2/16/23 03:49, Pierrick Bouvier wrote: > ctr_el0 access is privileged on this platform and fails as an illegal > instruction. > > Windows does not offer a way to flush data cache from userspace, and > only FlushInstructionCache is available in Windows API. > > The generic implementation of flush_idcache_range uses, > __builtin___clear_cache, which already use the FlushInstructionCache > function. So we rely on that. > > Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org> This is reasonable for now. I'll note that gcc does not yet support windows for aarch64, and I would guess this would be fixed for libgcc at such time as. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~ > --- > util/cacheflush.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/util/cacheflush.c b/util/cacheflush.c > index 2c2c73e085..0a0acd70fa 100644 > --- a/util/cacheflush.c > +++ b/util/cacheflush.c > @@ -121,8 +121,10 @@ static void sys_cache_info(int *isize, int *dsize) > static bool have_coherent_icache; > #endif > > -#if defined(__aarch64__) && !defined(CONFIG_DARWIN) > -/* Apple does not expose CTR_EL0, so we must use system interfaces. */ > +#if defined(__aarch64__) && !defined(CONFIG_DARWIN) && !defined(CONFIG_WIN32) > +/* Apple does not expose CTR_EL0, so we must use system interfaces. > + * Windows neither, but we use a generic implementation of flush_idcache_range > + * in this case. */ > static uint64_t save_ctr_el0; > static void arch_cache_info(int *isize, int *dsize) > { > @@ -225,7 +227,9 @@ static void __attribute__((constructor)) init_cache_info(void) > > /* Caches are coherent and do not require flushing; symbol inline. */ > > -#elif defined(__aarch64__) > +#elif defined(__aarch64__) && !defined(CONFIG_WIN32) > +/* For Windows, we use generic implementation of flush_idcache_range, that > + * performs a call to FlushInstructionCache, through __builtin___clear_cache */ > > #ifdef CONFIG_DARWIN > /* Apple does not expose CTR_EL0, so we must use system interfaces. */
On Thu, 16 Feb 2023 at 13:49, Pierrick Bouvier <pierrick.bouvier@linaro.org> wrote: > > ctr_el0 access is privileged on this platform and fails as an illegal > instruction. > > Windows does not offer a way to flush data cache from userspace, and > only FlushInstructionCache is available in Windows API. > > The generic implementation of flush_idcache_range uses, > __builtin___clear_cache, which already use the FlushInstructionCache > function. So we rely on that. > > Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org> > --- > util/cacheflush.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/util/cacheflush.c b/util/cacheflush.c > index 2c2c73e085..0a0acd70fa 100644 > --- a/util/cacheflush.c > +++ b/util/cacheflush.c > @@ -121,8 +121,10 @@ static void sys_cache_info(int *isize, int *dsize) > static bool have_coherent_icache; > #endif > > -#if defined(__aarch64__) && !defined(CONFIG_DARWIN) > -/* Apple does not expose CTR_EL0, so we must use system interfaces. */ > +#if defined(__aarch64__) && !defined(CONFIG_DARWIN) && !defined(CONFIG_WIN32) > +/* Apple does not expose CTR_EL0, so we must use system interfaces. > + * Windows neither, but we use a generic implementation of flush_idcache_range > + * in this case. */ QEMU multiline comment syntax requires the /* and */ to be on lines of their own (here and in your other comment). thanks -- PMM
On 2/17/23 16:32, Peter Maydell wrote: > On Thu, 16 Feb 2023 at 13:49, Pierrick Bouvier > <pierrick.bouvier@linaro.org> wrote: >> >> ctr_el0 access is privileged on this platform and fails as an illegal >> instruction. >> >> Windows does not offer a way to flush data cache from userspace, and >> only FlushInstructionCache is available in Windows API. >> >> The generic implementation of flush_idcache_range uses, >> __builtin___clear_cache, which already use the FlushInstructionCache >> function. So we rely on that. >> >> Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org> >> --- >> util/cacheflush.c | 10 +++++++--- >> 1 file changed, 7 insertions(+), 3 deletions(-) >> >> diff --git a/util/cacheflush.c b/util/cacheflush.c >> index 2c2c73e085..0a0acd70fa 100644 >> --- a/util/cacheflush.c >> +++ b/util/cacheflush.c >> @@ -121,8 +121,10 @@ static void sys_cache_info(int *isize, int *dsize) >> static bool have_coherent_icache; >> #endif >> >> -#if defined(__aarch64__) && !defined(CONFIG_DARWIN) >> -/* Apple does not expose CTR_EL0, so we must use system interfaces. */ >> +#if defined(__aarch64__) && !defined(CONFIG_DARWIN) && !defined(CONFIG_WIN32) >> +/* Apple does not expose CTR_EL0, so we must use system interfaces. >> + * Windows neither, but we use a generic implementation of flush_idcache_range >> + * in this case. */ > > QEMU multiline comment syntax requires the /* and */ to be > on lines of their own (here and in your other comment). > Sorry, I missed that point in QEMU coding style. Will update this 👍 > thanks > -- PMM
On 2/16/23 20:42, Richard Henderson wrote: > On 2/16/23 03:49, Pierrick Bouvier wrote: >> ctr_el0 access is privileged on this platform and fails as an illegal >> instruction. >> >> Windows does not offer a way to flush data cache from userspace, and >> only FlushInstructionCache is available in Windows API. >> >> The generic implementation of flush_idcache_range uses, >> __builtin___clear_cache, which already use the FlushInstructionCache >> function. So we rely on that. >> >> Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org> > > This is reasonable for now. I'll note that gcc does not yet support windows for aarch64, > and I would guess this would be fixed for libgcc at such time as. > > Reviewed-by: Richard Henderson <richard.henderson@linaro.org> > For completeness, and after asking to Microsoft, FlushInstructionCache does DCache-Clean-to-PoU + ICache-Invalidate-to-PoU, which is equivalent to calling dccvau + icivau. Thus, it's doing the right thing. Pierrick > > r~ > > >> --- >> util/cacheflush.c | 10 +++++++--- >> 1 file changed, 7 insertions(+), 3 deletions(-) >> >> diff --git a/util/cacheflush.c b/util/cacheflush.c >> index 2c2c73e085..0a0acd70fa 100644 >> --- a/util/cacheflush.c >> +++ b/util/cacheflush.c >> @@ -121,8 +121,10 @@ static void sys_cache_info(int *isize, int *dsize) >> static bool have_coherent_icache; >> #endif >> >> -#if defined(__aarch64__) && !defined(CONFIG_DARWIN) >> -/* Apple does not expose CTR_EL0, so we must use system interfaces. */ >> +#if defined(__aarch64__) && !defined(CONFIG_DARWIN) && !defined(CONFIG_WIN32) >> +/* Apple does not expose CTR_EL0, so we must use system interfaces. >> + * Windows neither, but we use a generic implementation of flush_idcache_range >> + * in this case. */ >> static uint64_t save_ctr_el0; >> static void arch_cache_info(int *isize, int *dsize) >> { >> @@ -225,7 +227,9 @@ static void __attribute__((constructor)) init_cache_info(void) >> >> /* Caches are coherent and do not require flushing; symbol inline. */ >> >> -#elif defined(__aarch64__) >> +#elif defined(__aarch64__) && !defined(CONFIG_WIN32) >> +/* For Windows, we use generic implementation of flush_idcache_range, that >> + * performs a call to FlushInstructionCache, through __builtin___clear_cache */ >> >> #ifdef CONFIG_DARWIN >> /* Apple does not expose CTR_EL0, so we must use system interfaces. */ >
diff --git a/util/cacheflush.c b/util/cacheflush.c index 2c2c73e085..0a0acd70fa 100644 --- a/util/cacheflush.c +++ b/util/cacheflush.c @@ -121,8 +121,10 @@ static void sys_cache_info(int *isize, int *dsize) static bool have_coherent_icache; #endif -#if defined(__aarch64__) && !defined(CONFIG_DARWIN) -/* Apple does not expose CTR_EL0, so we must use system interfaces. */ +#if defined(__aarch64__) && !defined(CONFIG_DARWIN) && !defined(CONFIG_WIN32) +/* Apple does not expose CTR_EL0, so we must use system interfaces. + * Windows neither, but we use a generic implementation of flush_idcache_range + * in this case. */ static uint64_t save_ctr_el0; static void arch_cache_info(int *isize, int *dsize) { @@ -225,7 +227,9 @@ static void __attribute__((constructor)) init_cache_info(void) /* Caches are coherent and do not require flushing; symbol inline. */ -#elif defined(__aarch64__) +#elif defined(__aarch64__) && !defined(CONFIG_WIN32) +/* For Windows, we use generic implementation of flush_idcache_range, that + * performs a call to FlushInstructionCache, through __builtin___clear_cache */ #ifdef CONFIG_DARWIN /* Apple does not expose CTR_EL0, so we must use system interfaces. */
ctr_el0 access is privileged on this platform and fails as an illegal instruction. Windows does not offer a way to flush data cache from userspace, and only FlushInstructionCache is available in Windows API. The generic implementation of flush_idcache_range uses, __builtin___clear_cache, which already use the FlushInstructionCache function. So we rely on that. Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org> --- util/cacheflush.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)