From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754047AbbIGPjV (ORCPT ); Mon, 7 Sep 2015 11:39:21 -0400 Received: from smtp.citrix.com ([66.165.176.89]:17747 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753950AbbIGPit (ORCPT ); Mon, 7 Sep 2015 11:38:49 -0400 X-IronPort-AV: E=Sophos;i="5.17,485,1437436800"; d="scan'208";a="298262369" From: Julien Grall To: CC: , , , , "Julien Grall" , David Vrabel , Russell King , Konrad Rzeszutek Wilk , Boris Ostrovsky Subject: [PATCH v4 14/20] xen/grant-table: Make it running on 64KB granularity Date: Mon, 7 Sep 2015 16:33:52 +0100 Message-ID: <1441640038-23615-15-git-send-email-julien.grall@citrix.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1441640038-23615-1-git-send-email-julien.grall@citrix.com> References: <1441640038-23615-1-git-send-email-julien.grall@citrix.com> MIME-Version: 1.0 Content-Type: text/plain X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The Xen interface is using 4KB page granularity. This means that each grant is 4KB. The current implementation allocates a Linux page per grant. On Linux using 64KB page granularity, only the first 4KB of the page will be used. We could decrease the memory wasted by sharing the page with multiple grant. It will require some care with the {Set,Clear}ForeignPage macro. Note that no changes has been made in the x86 code because both Linux and Xen will only use 4KB page granularity. Signed-off-by: Julien Grall Reviewed-by: David Vrabel Reviewed-by: Stefano Stabellini --- Cc: Stefano Stabellini Cc: Russell King Cc: Konrad Rzeszutek Wilk Cc: Boris Ostrovsky Changes in v3: - Add Stefano's reviewed-by Changes in v2 - Add David's reviewed-by --- arch/arm/xen/p2m.c | 6 +++--- drivers/xen/grant-table.c | 6 +++--- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c index 887596c..0ed01f2 100644 --- a/arch/arm/xen/p2m.c +++ b/arch/arm/xen/p2m.c @@ -93,8 +93,8 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, for (i = 0; i < count; i++) { if (map_ops[i].status) continue; - set_phys_to_machine(map_ops[i].host_addr >> PAGE_SHIFT, - map_ops[i].dev_bus_addr >> PAGE_SHIFT); + set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT, + map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT); } return 0; @@ -108,7 +108,7 @@ int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, int i; for (i = 0; i < count; i++) { - set_phys_to_machine(unmap_ops[i].host_addr >> PAGE_SHIFT, + set_phys_to_machine(unmap_ops[i].host_addr >> XEN_PAGE_SHIFT, INVALID_P2M_ENTRY); } diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 7b4e1cf..99ed9c2 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -642,7 +642,7 @@ int gnttab_setup_auto_xlat_frames(phys_addr_t addr) if (xen_auto_xlat_grant_frames.count) return -EINVAL; - vaddr = xen_remap(addr, PAGE_SIZE * max_nr_gframes); + vaddr = xen_remap(addr, XEN_PAGE_SIZE * max_nr_gframes); if (vaddr == NULL) { pr_warn("Failed to ioremap gnttab share frames (addr=%pa)!\n", &addr); @@ -654,7 +654,7 @@ int gnttab_setup_auto_xlat_frames(phys_addr_t addr) return -ENOMEM; } for (i = 0; i < max_nr_gframes; i++) - pfn[i] = PFN_DOWN(addr) + i; + pfn[i] = XEN_PFN_DOWN(addr) + i; xen_auto_xlat_grant_frames.vaddr = vaddr; xen_auto_xlat_grant_frames.pfn = pfn; @@ -1004,7 +1004,7 @@ static void gnttab_request_version(void) { /* Only version 1 is used, which will always be available. */ grant_table_version = 1; - grefs_per_grant_frame = PAGE_SIZE / sizeof(struct grant_entry_v1); + grefs_per_grant_frame = XEN_PAGE_SIZE / sizeof(struct grant_entry_v1); gnttab_interface = &gnttab_v1_ops; pr_info("Grant tables using version %d layout\n", grant_table_version); -- 2.1.4 From mboxrd@z Thu Jan 1 00:00:00 1970 From: julien.grall@citrix.com (Julien Grall) Date: Mon, 7 Sep 2015 16:33:52 +0100 Subject: [PATCH v4 14/20] xen/grant-table: Make it running on 64KB granularity In-Reply-To: <1441640038-23615-1-git-send-email-julien.grall@citrix.com> References: <1441640038-23615-1-git-send-email-julien.grall@citrix.com> Message-ID: <1441640038-23615-15-git-send-email-julien.grall@citrix.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The Xen interface is using 4KB page granularity. This means that each grant is 4KB. The current implementation allocates a Linux page per grant. On Linux using 64KB page granularity, only the first 4KB of the page will be used. We could decrease the memory wasted by sharing the page with multiple grant. It will require some care with the {Set,Clear}ForeignPage macro. Note that no changes has been made in the x86 code because both Linux and Xen will only use 4KB page granularity. Signed-off-by: Julien Grall Reviewed-by: David Vrabel Reviewed-by: Stefano Stabellini --- Cc: Stefano Stabellini Cc: Russell King Cc: Konrad Rzeszutek Wilk Cc: Boris Ostrovsky Changes in v3: - Add Stefano's reviewed-by Changes in v2 - Add David's reviewed-by --- arch/arm/xen/p2m.c | 6 +++--- drivers/xen/grant-table.c | 6 +++--- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c index 887596c..0ed01f2 100644 --- a/arch/arm/xen/p2m.c +++ b/arch/arm/xen/p2m.c @@ -93,8 +93,8 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, for (i = 0; i < count; i++) { if (map_ops[i].status) continue; - set_phys_to_machine(map_ops[i].host_addr >> PAGE_SHIFT, - map_ops[i].dev_bus_addr >> PAGE_SHIFT); + set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT, + map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT); } return 0; @@ -108,7 +108,7 @@ int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, int i; for (i = 0; i < count; i++) { - set_phys_to_machine(unmap_ops[i].host_addr >> PAGE_SHIFT, + set_phys_to_machine(unmap_ops[i].host_addr >> XEN_PAGE_SHIFT, INVALID_P2M_ENTRY); } diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 7b4e1cf..99ed9c2 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -642,7 +642,7 @@ int gnttab_setup_auto_xlat_frames(phys_addr_t addr) if (xen_auto_xlat_grant_frames.count) return -EINVAL; - vaddr = xen_remap(addr, PAGE_SIZE * max_nr_gframes); + vaddr = xen_remap(addr, XEN_PAGE_SIZE * max_nr_gframes); if (vaddr == NULL) { pr_warn("Failed to ioremap gnttab share frames (addr=%pa)!\n", &addr); @@ -654,7 +654,7 @@ int gnttab_setup_auto_xlat_frames(phys_addr_t addr) return -ENOMEM; } for (i = 0; i < max_nr_gframes; i++) - pfn[i] = PFN_DOWN(addr) + i; + pfn[i] = XEN_PFN_DOWN(addr) + i; xen_auto_xlat_grant_frames.vaddr = vaddr; xen_auto_xlat_grant_frames.pfn = pfn; @@ -1004,7 +1004,7 @@ static void gnttab_request_version(void) { /* Only version 1 is used, which will always be available. */ grant_table_version = 1; - grefs_per_grant_frame = PAGE_SIZE / sizeof(struct grant_entry_v1); + grefs_per_grant_frame = XEN_PAGE_SIZE / sizeof(struct grant_entry_v1); gnttab_interface = &gnttab_v1_ops; pr_info("Grant tables using version %d layout\n", grant_table_version); -- 2.1.4