| Message ID | 1344337036-22244-9-git-send-email-agraf@suse.de |
|---|---|
| State | New, archived |
| Headers | show |
On 08/07/2012 05:57 AM, Alexander Graf wrote: > When we map a page that wasn't icache cleared before, do so when first > mapping it in KVM using the same information bits as the Linux mapping > logic. That way we are 100% sure that any page we map does not have stale > entries in the icache. > > What we really would need is a method to flush the icache only when we > actually map a page executable for the guest. But with the current > abstraction that is hard to do, and this way we don't have a huge performance > penalty, so better be safe now and micro optimize things later. > > Signed-off-by: Alexander Graf <agraf@suse.de> > --- > arch/powerpc/include/asm/kvm_host.h | 10 ++++++++++ > arch/powerpc/mm/mem.c | 1 + > 2 files changed, 11 insertions(+), 0 deletions(-) > > diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h > index ed75bc9..c0a2fc1 100644 > --- a/arch/powerpc/include/asm/kvm_host.h > +++ b/arch/powerpc/include/asm/kvm_host.h > @@ -33,6 +33,7 @@ > #include <asm/kvm_asm.h> > #include <asm/processor.h> > #include <asm/page.h> > +#include <asm/cacheflush.h> > > #define KVM_MAX_VCPUS NR_CPUS > #define KVM_MAX_VCORES NR_CPUS > @@ -550,5 +551,14 @@ struct kvm_vcpu_arch { > #define KVM_MMIO_REG_FQPR 0x0060 > > #define __KVM_HAVE_ARCH_WQP > +#define __KVM_HAVE_ARCH_MAP_PAGE > +static inline void kvm_arch_map_page(struct page *page) > +{ > + /* Need to invalidate the icache for new pages */ > + if (!test_bit(PG_arch_1, &page->flags)) { > + flush_dcache_icache_page(page); > + set_bit(PG_arch_1, &page->flags); > + } > +} Shouldn't this test CPU_FTR_COHERENT_ICACHE? -Scott -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 07.08.2012, at 23:01, Scott Wood <scottwood@freescale.com> wrote: > On 08/07/2012 05:57 AM, Alexander Graf wrote: >> When we map a page that wasn't icache cleared before, do so when first >> mapping it in KVM using the same information bits as the Linux mapping >> logic. That way we are 100% sure that any page we map does not have stale >> entries in the icache. >> >> What we really would need is a method to flush the icache only when we >> actually map a page executable for the guest. But with the current >> abstraction that is hard to do, and this way we don't have a huge performance >> penalty, so better be safe now and micro optimize things later. >> >> Signed-off-by: Alexander Graf <agraf@suse.de> >> --- >> arch/powerpc/include/asm/kvm_host.h | 10 ++++++++++ >> arch/powerpc/mm/mem.c | 1 + >> 2 files changed, 11 insertions(+), 0 deletions(-) >> >> diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h >> index ed75bc9..c0a2fc1 100644 >> --- a/arch/powerpc/include/asm/kvm_host.h >> +++ b/arch/powerpc/include/asm/kvm_host.h >> @@ -33,6 +33,7 @@ >> #include <asm/kvm_asm.h> >> #include <asm/processor.h> >> #include <asm/page.h> >> +#include <asm/cacheflush.h> >> >> #define KVM_MAX_VCPUS NR_CPUS >> #define KVM_MAX_VCORES NR_CPUS >> @@ -550,5 +551,14 @@ struct kvm_vcpu_arch { >> #define KVM_MMIO_REG_FQPR 0x0060 >> >> #define __KVM_HAVE_ARCH_WQP >> +#define __KVM_HAVE_ARCH_MAP_PAGE >> +static inline void kvm_arch_map_page(struct page *page) >> +{ >> + /* Need to invalidate the icache for new pages */ >> + if (!test_bit(PG_arch_1, &page->flags)) { >> + flush_dcache_icache_page(page); >> + set_bit(PG_arch_1, &page->flags); >> + } >> +} > > Shouldn't this test CPU_FTR_COHERENT_ICACHE? flush_icache_range checks for it a bit further down the code stream. I mostly modeled things the same way as set_pre_filter. Alex -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index ed75bc9..c0a2fc1 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -33,6 +33,7 @@ #include <asm/kvm_asm.h> #include <asm/processor.h> #include <asm/page.h> +#include <asm/cacheflush.h> #define KVM_MAX_VCPUS NR_CPUS #define KVM_MAX_VCORES NR_CPUS @@ -550,5 +551,14 @@ struct kvm_vcpu_arch { #define KVM_MMIO_REG_FQPR 0x0060 #define __KVM_HAVE_ARCH_WQP +#define __KVM_HAVE_ARCH_MAP_PAGE +static inline void kvm_arch_map_page(struct page *page) +{ + /* Need to invalidate the icache for new pages */ + if (!test_bit(PG_arch_1, &page->flags)) { + flush_dcache_icache_page(page); + set_bit(PG_arch_1, &page->flags); + } +} #endif /* __POWERPC_KVM_HOST_H__ */ diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index baaafde..fbdad0e 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -469,6 +469,7 @@ void flush_dcache_icache_page(struct page *page) __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT); #endif } +EXPORT_SYMBOL(flush_dcache_icache_page); void clear_user_page(void *page, unsigned long vaddr, struct page *pg) {
When we map a page that wasn't icache cleared before, do so when first mapping it in KVM using the same information bits as the Linux mapping logic. That way we are 100% sure that any page we map does not have stale entries in the icache. What we really would need is a method to flush the icache only when we actually map a page executable for the guest. But with the current abstraction that is hard to do, and this way we don't have a huge performance penalty, so better be safe now and micro optimize things later. Signed-off-by: Alexander Graf <agraf@suse.de> --- arch/powerpc/include/asm/kvm_host.h | 10 ++++++++++ arch/powerpc/mm/mem.c | 1 + 2 files changed, 11 insertions(+), 0 deletions(-)