KVM: PPC: Add cache flush on page map

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.

Signed-off-by: Alexander Graf <[e-mail]>

arch/powerpc/include/asm/kvm_host.h

···
 #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

arch/powerpc/include/asm/kvm_ppc.h

···
 void kvmppc_free_lpid(long lpid);
 void kvmppc_init_lpid(unsigned long nr_lpids);
 
+static inline void kvmppc_mmu_flush_icache(pfn_t pfn)
+{
+	/* Clear i-cache for new pages */
+	struct page *page;
+	page = pfn_to_page(pfn);
+	if (!test_bit(PG_arch_1, &page->flags)) {
+		flush_dcache_icache_page(page);
+		set_bit(PG_arch_1, &page->flags);
+	}
+}
+
+
 #endif /* __POWERPC_KVM_PPC_H__ */

arch/powerpc/kvm/book3s_32_mmu_host.c

···
 		pteg1 |= PP_RWRX;
 	}
 
+	if (orig_pte->may_execute)
+		kvmppc_mmu_flush_icache(hpaddr >> PAGE_SHIFT);
+
 	local_irq_disable();
 
 	if (pteg[rr]) {

arch/powerpc/kvm/book3s_64_mmu_host.c

···
 
 	if (!orig_pte->may_execute)
 		rflags |= HPTE_R_N;
+	else
+		kvmppc_mmu_flush_icache(hpaddr >> PAGE_SHIFT);
 
 	hash = hpt_hash(va, PTE_SIZE, MMU_SEGSIZE_256M);
 

arch/powerpc/kvm/e500_tlb.c

···
 
 	kvmppc_e500_setup_stlbe(&vcpu_e500->vcpu, gtlbe, tsize,
 				ref, gvaddr, stlbe);
+
+	/* Clear i-cache for new pages */
+	kvmppc_mmu_flush_icache(pfn);
 }
 
 /* XXX only map the one-one case, for now use TLB0 */

arch/powerpc/mm/mem.c

···
 	__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)
 {