From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 7E91CAD23 for ; Thu, 27 Oct 2022 17:07:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9D20C433D6; Thu, 27 Oct 2022 17:07:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666890469; bh=e6Kwfj8b9VtoSQA1NKD3Sf47xiVDNYYBJjNUh04cwEc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RrbduayKm4FyaCB/oMj1qRhgO35C2UxtQ9xrzo3pfq3r0884wsYbvGXDPG46kjalV aGNGUCO6ATn/NmWRHcx6VeYU66sMElvN4wKjDm8J1G4CvmAPIDtVQxGDloFF1lxnow 1OcrIFnQbakrEVmprdcwm9ya1m9lpS3Lt6FmbIpw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Juergen Gross , "Peter Zijlstra (Intel)" , Boris Ostrovsky , Sasha Levin Subject: [PATCH 5.10 60/79] xen: assume XENFEAT_gnttab_map_avail_bits being set for pv guests Date: Thu, 27 Oct 2022 18:56:10 +0200 Message-Id: <20221027165056.337615748@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221027165054.270676357@linuxfoundation.org> References: <20221027165054.270676357@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Juergen Gross [ Upstream commit 30dcc56bba911db561c35d4131baf983a41023f8 ] XENFEAT_gnttab_map_avail_bits is always set in Xen 4.0 and newer. Remove coding assuming it might be zero. Signed-off-by: Juergen Gross Acked-by: Peter Zijlstra (Intel) Reviewed-by: Boris Ostrovsky Link: https://lore.kernel.org/r/20210730071804.4302-4-jgross@suse.com Signed-off-by: Juergen Gross Stable-dep-of: 5c13a4a0291b ("xen/gntdev: Accommodate VMA splitting") Signed-off-by: Sasha Levin --- drivers/xen/gntdev.c | 36 ++---------------------------------- 1 file changed, 2 insertions(+), 34 deletions(-) diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 54fee4087bf1..5dd9d1ac755e 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -289,20 +289,13 @@ static int find_grant_ptes(pte_t *pte, unsigned long addr, void *data) { struct gntdev_grant_map *map = data; unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT; - int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte; + int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte | + (1 << _GNTMAP_guest_avail0); u64 pte_maddr; BUG_ON(pgnr >= map->count); pte_maddr = arbitrary_virt_to_machine(pte).maddr; - /* - * Set the PTE as special to force get_user_pages_fast() fall - * back to the slow path. If this is not supported as part of - * the grant map, it will be done afterwards. - */ - if (xen_feature(XENFEAT_gnttab_map_avail_bits)) - flags |= (1 << _GNTMAP_guest_avail0); - gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags, map->grants[pgnr].ref, map->grants[pgnr].domid); @@ -311,14 +304,6 @@ static int find_grant_ptes(pte_t *pte, unsigned long addr, void *data) return 0; } -#ifdef CONFIG_X86 -static int set_grant_ptes_as_special(pte_t *pte, unsigned long addr, void *data) -{ - set_pte_at(current->mm, addr, pte, pte_mkspecial(*pte)); - return 0; -} -#endif - int gntdev_map_grant_pages(struct gntdev_grant_map *map) { size_t alloced = 0; @@ -1102,23 +1087,6 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) err = vm_map_pages_zero(vma, map->pages, map->count); if (err) goto out_put_map; - } else { -#ifdef CONFIG_X86 - /* - * If the PTEs were not made special by the grant map - * hypercall, do so here. - * - * This is racy since the mapping is already visible - * to userspace but userspace should be well-behaved - * enough to not touch it until the mmap() call - * returns. - */ - if (!xen_feature(XENFEAT_gnttab_map_avail_bits)) { - apply_to_page_range(vma->vm_mm, vma->vm_start, - vma->vm_end - vma->vm_start, - set_grant_ptes_as_special, NULL); - } -#endif } return 0; -- 2.35.1