From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.skyhub.de ([5.9.137.197]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1h7Ppk-0005oc-UX for kexec@lists.infradead.org; Fri, 22 Mar 2019 19:28:06 +0000 Date: Fri, 22 Mar 2019 20:28:00 +0100 From: Borislav Petkov Subject: Re: [PATCH 2/3 v9] resource: add the new I/O resource descriptor 'IORES_DESC_RESERVED' Message-ID: <20190322192800.GM12472@zn.tnic> References: <20190321103309.27883-1-lijiang@redhat.com> <20190321103309.27883-3-lijiang@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190321103309.27883-3-lijiang@redhat.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Lianbo Jiang Cc: Thomas.Lendacky@amd.com, x86@kernel.org, bhe@redhat.com, peterz@infradead.org, dave.hansen@linux.intel.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, mingo@redhat.com, luto@kernel.org, hpa@zytor.com, tglx@linutronix.de, dyoung@redhat.com, akpm@linux-foundation.org On Thu, Mar 21, 2019 at 06:33:08PM +0800, Lianbo Jiang wrote: > When doing kexec_file_load, the first kernel needs to pass the e820 Please end function names with parentheses. > reserved ranges to the second kernel. ... because... ? > But kernel can not exactly match the e820 reserved ranges ^ the > when walking through the iomem resources with the descriptor > 'IORES_DESC_NONE', because several e820 types( e.g. > E820_TYPE_RESERVED_KERN/E820_TYPE_RAM/E820_TYPE_UNUSABLE/E820 > _TYPE_RESERVED) are converted to the descriptor 'IORES_DESC_NONE'. > It may pass these four types to the kdump kernel, that is not desired result. Rewrite that sentence. > So, this patch adds a new I/O resource descriptor 'IORES_DESC_RESERVED' Avoid having "This patch" or "This commit" in the commit message. It is tautologically useless. Also, do $ git grep 'This patch' Documentation/process for more details. > for the iomem resources search interfaces. It is helpful to exactly > match the reserved resource ranges when walking through iomem resources. > > In addition, since the new descriptor 'IORES_DESC_RESERVED' is introduced, > these code originally related to the descriptor 'IORES_DESC_NONE' need to "the code" > be updated. > Otherwise, it will be easily confused and also cause some errors. What errors? > Because the 'E820_TYPE_RESERVED' type is converted to the new > descriptor 'IORES_DESC_RESERVED' instead of 'IORES_DESC_NONE', it has been > changed. That sentence I cannot parse. > Suggested-by: Borislav Petkov > Signed-off-by: Lianbo Jiang > --- > arch/x86/kernel/e820.c | 2 +- > include/linux/ioport.h | 1 + > kernel/resource.c | 6 +++--- > 3 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c > index 2879e234e193..16fcde196243 100644 > --- a/arch/x86/kernel/e820.c > +++ b/arch/x86/kernel/e820.c > @@ -1050,10 +1050,10 @@ static unsigned long __init e820_type_to_iores_desc(struct e820_entry *entry) > case E820_TYPE_NVS: return IORES_DESC_ACPI_NV_STORAGE; > case E820_TYPE_PMEM: return IORES_DESC_PERSISTENT_MEMORY; > case E820_TYPE_PRAM: return IORES_DESC_PERSISTENT_MEMORY_LEGACY; > + case E820_TYPE_RESERVED: return IORES_DESC_RESERVED; > case E820_TYPE_RESERVED_KERN: /* Fall-through: */ > case E820_TYPE_RAM: /* Fall-through: */ > case E820_TYPE_UNUSABLE: /* Fall-through: */ > - case E820_TYPE_RESERVED: /* Fall-through: */ > default: return IORES_DESC_NONE; > } > } > diff --git a/include/linux/ioport.h b/include/linux/ioport.h > index da0ebaec25f0..6ed59de48bd5 100644 > --- a/include/linux/ioport.h > +++ b/include/linux/ioport.h > @@ -133,6 +133,7 @@ enum { > IORES_DESC_PERSISTENT_MEMORY_LEGACY = 5, > IORES_DESC_DEVICE_PRIVATE_MEMORY = 6, > IORES_DESC_DEVICE_PUBLIC_MEMORY = 7, > + IORES_DESC_RESERVED = 8, > }; > > /* helpers to define resources */ IORES_DESC_RESERVED is supposed to represent E820_TYPE_RESERVED. And if that is the case, then all three hunks below look wrong to me. If you want to pass E820_TYPE_RESERVED ranges, then do that explicitly. > diff --git a/kernel/resource.c b/kernel/resource.c > index e81b17b53fa5..ee7348761858 100644 > --- a/kernel/resource.c > +++ b/kernel/resource.c > @@ -990,7 +990,7 @@ __reserve_region_with_split(struct resource *root, resource_size_t start, > res->start = start; > res->end = end; > res->flags = type | IORESOURCE_BUSY; > - res->desc = IORES_DESC_NONE; > + res->desc = IORES_DESC_RESERVED; > > while (1) { > > @@ -1025,7 +1025,7 @@ __reserve_region_with_split(struct resource *root, resource_size_t start, > next_res->start = conflict->end + 1; > next_res->end = end; > next_res->flags = type | IORESOURCE_BUSY; > - next_res->desc = IORES_DESC_NONE; > + next_res->desc = IORES_DESC_RESERVED; > } > } else { > res->start = conflict->end + 1; > @@ -1488,7 +1488,7 @@ static int __init reserve_setup(char *str) > res->start = io_start; > res->end = io_start + io_num - 1; > res->flags |= IORESOURCE_BUSY; > - res->desc = IORES_DESC_NONE; > + res->desc = IORES_DESC_RESERVED; > res->child = NULL; > if (request_resource(parent, res) == 0) > reserved = x+1; > -- > 2.17.1 > -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply. _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec