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@xxxxxxx>
---
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);
+ }
+}
#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)
{
--
1.6.0.2
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