From patchwork Tue Dec 19 16:10:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Durrant X-Patchwork-Id: 13498520 Received: from mail.xenproject.org (mail.xenproject.org [104.130.215.37]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9A6E320315; Tue, 19 Dec 2023 16:40:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=xen.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=xen.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=xen.org header.i=@xen.org header.b="hELw3H6+" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xen.org; s=20200302mail; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-Id:Date:Subject:To:From; bh=DVmkuHvAJAn35Oz9caMUxenePj8iuuNulYJyd17+sk4=; b=hELw3H6+7H3fgr0HLX/hixtl3S d6PLuXRuq975u9PS8/HFZhfPa4UTHssM5P82WWdErrzdixqXBnb2XgklmU6m+VzxLAng/jfkC42RX FFRybzrhr1z2atb4q+A9FvzN+HJeNxreWzYPP5AQD3O3DXl075aLIwithnmnFWer+pqE=; Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1rFcjq-0005Lg-80; Tue, 19 Dec 2023 16:14:34 +0000 Received: from 54-240-197-226.amazon.com ([54.240.197.226] helo=REM-PW02S00X.ant.amazon.com) by xenbits.xenproject.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1rFcjp-0005h9-V6; Tue, 19 Dec 2023 16:14:34 +0000 From: Paul Durrant To: Paolo Bonzini , Jonathan Corbet , Sean Christopherson , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , David Woodhouse , Paul Durrant , Shuah Khan , kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH v11 01/19] KVM: pfncache: Add a map helper function Date: Tue, 19 Dec 2023 16:10:51 +0000 Message-Id: <20231219161109.1318-2-paul@xen.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231219161109.1318-1-paul@xen.org> References: <20231219161109.1318-1-paul@xen.org> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Paul Durrant There is a pfncache unmap helper but mapping is open-coded. Arguably this is fine because mapping is done in only one place, hva_to_pfn_retry(), but adding the helper does make that function more readable. No functional change intended. Signed-off-by: Paul Durrant Reviewed-by: David Woodhouse --- Cc: Sean Christopherson Cc: David Woodhouse Cc: Paolo Bonzini v8: - Re-work commit comment. - Fix CONFIG_HAS_IOMEM=n build. --- virt/kvm/pfncache.c | 47 ++++++++++++++++++++++++++++----------------- 1 file changed, 29 insertions(+), 18 deletions(-) diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c index 2d6aba677830..10842f1eeeae 100644 --- a/virt/kvm/pfncache.c +++ b/virt/kvm/pfncache.c @@ -96,17 +96,32 @@ bool kvm_gpc_check(struct gfn_to_pfn_cache *gpc, unsigned long len) } EXPORT_SYMBOL_GPL(kvm_gpc_check); -static void gpc_unmap_khva(kvm_pfn_t pfn, void *khva) +static void *gpc_map(kvm_pfn_t pfn) { - /* Unmap the old pfn/page if it was mapped before. */ - if (!is_error_noslot_pfn(pfn) && khva) { - if (pfn_valid(pfn)) - kunmap(pfn_to_page(pfn)); + if (pfn_valid(pfn)) + return kmap(pfn_to_page(pfn)); + #ifdef CONFIG_HAS_IOMEM - else - memunmap(khva); + return memremap(pfn_to_hpa(pfn), PAGE_SIZE, MEMREMAP_WB); +#else + return NULL; #endif +} + +static void gpc_unmap(kvm_pfn_t pfn, void *khva) +{ + /* Unmap the old pfn/page if it was mapped before. */ + if (is_error_noslot_pfn(pfn) || !khva) + return; + + if (pfn_valid(pfn)) { + kunmap(pfn_to_page(pfn)); + return; } + +#ifdef CONFIG_HAS_IOMEM + memunmap(khva); +#endif } static inline bool mmu_notifier_retry_cache(struct kvm *kvm, unsigned long mmu_seq) @@ -175,7 +190,7 @@ static kvm_pfn_t hva_to_pfn_retry(struct gfn_to_pfn_cache *gpc) * the existing mapping and didn't create a new one. */ if (new_khva != old_khva) - gpc_unmap_khva(new_pfn, new_khva); + gpc_unmap(new_pfn, new_khva); kvm_release_pfn_clean(new_pfn); @@ -193,15 +208,11 @@ static kvm_pfn_t hva_to_pfn_retry(struct gfn_to_pfn_cache *gpc) * too must be done outside of gpc->lock! */ if (gpc->usage & KVM_HOST_USES_PFN) { - if (new_pfn == gpc->pfn) { + if (new_pfn == gpc->pfn) new_khva = old_khva; - } else if (pfn_valid(new_pfn)) { - new_khva = kmap(pfn_to_page(new_pfn)); -#ifdef CONFIG_HAS_IOMEM - } else { - new_khva = memremap(pfn_to_hpa(new_pfn), PAGE_SIZE, MEMREMAP_WB); -#endif - } + else + new_khva = gpc_map(new_pfn); + if (!new_khva) { kvm_release_pfn_clean(new_pfn); goto out_error; @@ -326,7 +337,7 @@ static int __kvm_gpc_refresh(struct gfn_to_pfn_cache *gpc, gpa_t gpa, mutex_unlock(&gpc->refresh_lock); if (unmap_old) - gpc_unmap_khva(old_pfn, old_khva); + gpc_unmap(old_pfn, old_khva); return ret; } @@ -412,7 +423,7 @@ void kvm_gpc_deactivate(struct gfn_to_pfn_cache *gpc) list_del(&gpc->list); spin_unlock(&kvm->gpc_lock); - gpc_unmap_khva(old_pfn, old_khva); + gpc_unmap(old_pfn, old_khva); } } EXPORT_SYMBOL_GPL(kvm_gpc_deactivate);