KVM: SEV: Add cond_resched() to loop in sev_clflush_pages()

Add resched to avoid warning from sev_clflush_pages() with large number
of pages.

Signed-off-by: Peter Gonda <pgonda@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

Message-Id: <20220330164306.2376085-1-pgonda@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/svm/sev.c

@@ -465,6 +465,7 @@ static void sev_clflush_pages(struct page *pages[], unsigned long npages)
 		page_virtual = kmap_atomic(pages[i]);
 		clflush_cache_range(page_virtual, PAGE_SIZE);
 		kunmap_atomic(page_virtual);
+		cond_resched();
 	}
 }