Re: [PATCH 0/2 RESEND v7] add reserved e820 ranges to the kdump kernel e820 table
在 2018年11月27日 02:54, Dave Hansen 写道: > On 11/23/18 9:12 PM, Lianbo Jiang wrote: >> These patches add the new I/O resource descriptor 'IORES_DESC_RESERVED' >> for the iomem resources search interfaces, and in order to make it still >> work after the new descriptor is added, these codes originally related >> to 'IORES_DESC_NONE' have been updated. > > This is rather anemic "0/" text. Could you please include some more > background in here? The 2/2 patch is pretty good in this regard, but it > needs to be here, too. > Thanks for your comment. Originally, this patch added the e820 reserved ranges by accurately comparing a string. It only modifies fewer code paths. Please refer to patch v6. https://lore.kernel.org/lkml/20181114072926.13312-2-liji...@redhat.com/ Because the string comparison is fragile and error-prone, this patch used the solution that adds a new descriptor 'IORES_DESC_RESERVED'. Please refer to this link: https://lore.kernel.org/lkml/20181120192935.gk2...@zn.tnic/ When passing the e820 reserved ranges to the second kernel, why does it need to compare strings accurately or add a new descriptor 'IORES_DESC_RESERVED'? -The reason is that it can not exactly match the e820 reserved resource ranges when walking through iomem resources with the descriptor 'IORES_DESC_NONE'. Thanks. Lianbo
Re: [PATCH 0/2 RESEND v7] add reserved e820 ranges to the kdump kernel e820 table
On 11/23/18 9:12 PM, Lianbo Jiang wrote: > These patches add the new I/O resource descriptor 'IORES_DESC_RESERVED' > for the iomem resources search interfaces, and in order to make it still > work after the new descriptor is added, these codes originally related > to 'IORES_DESC_NONE' have been updated. This is rather anemic "0/" text. Could you please include some more background in here? The 2/2 patch is pretty good in this regard, but it needs to be here, too.
Re: [PATCH 0/2 RESEND v7] add reserved e820 ranges to the kdump kernel e820 table
On Mon, Nov 26, 2018 at 09:44:46AM -0800, Dave Hansen wrote: > On 11/23/18 9:12 PM, Lianbo Jiang wrote: > > These patches add the new I/O resource descriptor 'IORES_DESC_RESERVED' > > for the iomem resources search interfaces, and in order to make it still > > work after the new descriptor is added, these codes originally related > > to 'IORES_DESC_NONE' have been updated. > > I'm having a really hard time figuring out what problem these patches solve. > > What end-user visible behavior does this set change? Yeah, that was a long process of digging out the "why". I'd recommend reading the previous threads and, more specifically: https://lkml.kernel.org/r/cabhmzuuscs3juzusm5y6eyjk6weo7mjj5-eakgvbw0qee%2b3...@mail.gmail.com in short: we need to export e820 reserved ranges to the second kernel so that it can talk to PCI devices properly. (And I'm wondering how it did work until now...) -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.
Re: [PATCH 0/2 RESEND v7] add reserved e820 ranges to the kdump kernel e820 table
On 11/23/18 9:12 PM, Lianbo Jiang wrote: > These patches add the new I/O resource descriptor 'IORES_DESC_RESERVED' > for the iomem resources search interfaces, and in order to make it still > work after the new descriptor is added, these codes originally related > to 'IORES_DESC_NONE' have been updated. I'm having a really hard time figuring out what problem these patches solve. What end-user visible behavior does this set change?
[PATCH 0/2 RESEND v7] add reserved e820 ranges to the kdump kernel e820 table
These patches add the new I/O resource descriptor 'IORES_DESC_RESERVED' for the iomem resources search interfaces, and in order to make it still work after the new descriptor is added, these codes originally related to 'IORES_DESC_NONE' have been updated. In addition, for the MMCONFIG issue and the SME kdump issue, it is necessary to pass the e820 reserved ranges to kdump kernel. Changes since v1: 1. Modified the value of flags to "0", when walking through the whole tree for e820 reserved ranges. Changes since v2: 1. Modified the value of flags to "0", when walking through the whole tree for e820 reserved ranges. 2. Modified the invalid SOB chain issue. Changes since v3: 1. Dropped [PATCH 1/3 v3] resource: fix an error which walks through iomem resources. Please refer to this commit <010a93bf97c7> "resource: Fix find_next_iomem_res() iteration issue" Changes since v4: 1. Improve the patch log, and add kernel log. Changes since v5: 1. Rewrite these patches log. Changes since v6: 1. Modify the [PATCH 1/2], and add the new I/O resource descriptor 'IORES_DESC_RESERVED' for the iomem resources search interfaces, and also updates these codes relates to 'IORES_DESC_NONE'. 2. Modify the [PATCH 2/2], and walk through io resource based on the new descriptor 'IORES_DESC_RESERVED'. 3. Update patch log. Lianbo Jiang (2): resource: add the new I/O resource descriptor 'IORES_DESC_RESERVED' x86/kexec_file: add reserved e820 ranges to kdump kernel e820 table arch/ia64/kernel/efi.c | 4 arch/x86/kernel/crash.c | 6 ++ arch/x86/kernel/e820.c | 2 +- arch/x86/mm/ioremap.c | 9 - include/linux/ioport.h | 1 + kernel/resource.c | 6 +++--- 6 files changed, 23 insertions(+), 5 deletions(-) -- 2.17.1
