LKML Archive on lore.kernel.org
 help / color / Atom feed
From: "bhe@redhat.com" <bhe@redhat.com>
To: Junichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Borislav Petkov <bp@alien8.de>, Dave Young <dyoung@redhat.com>,
	"fanc.fnst@cn.fujitsu.com" <fanc.fnst@cn.fujitsu.com>,
	"kasong@redhat.com" <kasong@redhat.com>,
	"x86@kernel.org" <x86@kernel.org>,
	"kexec@lists.infradead.org" <kexec@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] x86/boot: Use EFI setup data if provided
Date: Thu, 28 Mar 2019 14:43:43 +0800
Message-ID: <20190328064343.GA1877@MiWiFi-R3L-srv> (raw)
In-Reply-To: <73322ba9-e436-68db-7863-afd31607d969@ce.jp.nec.com>

On 03/28/19 at 04:17am, Junichi Nomura wrote:
> On 2019/03/27 10:48, bhe@redhat.com wrote:
> >>> So efi_get_rsdp_addr() needs to be refactored in such a way so that at
> >>> least the loop towards the end gets carved out into a separate function
> >>> - __efi_get_rsdp_addr() or so - which gets config_tables, nr_tables and
> >>> size as arguments and finds the RSDP address in the kexec-ed kernel.
> >>
> >> You need to carve out the loop at the end and make it into a separate
> >> __efi_get_rsdp_addr() function which gets the physical or the virtual
> >> address.
> > 
> > I guess Boris is suggesting code like below. Please correct me if I am
> > wrong.
> > 
> > static acpi_physical_address _efi_get_rsdp_addr(efi_config_table tbl, ...)
> > {
> > 	/* Get EFI tables from systab. */
> > 	for (i = 0; i < nr_tables; i++) {
> > 		...
> > 	}
> > 	return rsdp_addr;
> > }
> > 
> > static acpi_physical_address efi_get_rsdp_addr(void)
> > {
> > 	...
> > 	/* Get systab from boot params. */		
> > 	...
> > 	/* Handle EFI bitness properly */
> > 	...
> > 	return _efi_get_rsdp_addr();
> > }
> > 
> > 
> > static acpi_physical_address kexec_get_rsdp_addr(void)
> > {
> > 	if (!is_kexec_booted)
> > 		return 0;
> > 
> > 	efi_get_setup_data_addr();
> > 	...
> > 	/* Handle EFI bitness properly */
> > 	...
> > 	return _efi_get_rsdp_addr();
> > }
> 
> I still don't get it... We still need systab for kexec case as well
> to get nr_tables. Don't we?

Yes, simpler.

As Dave replied in another mail, efi/kexec is only added for x86_64. See
how it does in setup_linux_system_parameters() of kexec_tools utility,
and we only have bzImage64 handling in kernel for kexec_file loading,
see prepare_add_efi_setup_data().

You may only need to get kexec ei_info to use directly.

> 
> > acpi_physical_address get_rsdp_addr(void)
> > {
> >          acpi_physical_address pa;
> > 
> >          pa = get_acpi_rsdp();
> > 
> >          if (!pa)
> >                  pa = boot_params->acpi_rsdp_addr;
> > 
> > 
> > 	/**
> > 	/*I think here we should check if it's kexec booted firstly.
> > 	 * Skip it if not kexec. this can avoid the wrong kexec virt
> > 	 * addr parsing./
> >          if (!pa)
> >                  pa = kexec_get_rdsp_addr();             <--- new function
> > 
> >          if (!pa)
> >                  pa = efi_get_rsdp_addr();
> > 
> 
> Shouldn't t efi_get_rsdp_addr() check "is_kexec_booted" and exit
> early so that it never tries to use virtual config_tables pointer
> if for some unknown resason kexec_get_rsdp_addr() failed.

Well, you can just call your efi_get_setup_data_addr() in
kexec_get_rdsp_addr(), if succeed, go ahead to read ei_info and call
_efi_get_rsdp_addr(). If failed, return to try efi_get_rsdp_addr().

> 
> Currently I check "is_kexec_booted" by subset of efi_get_setup_data_addr().
> Do you know a simpler way to check "is_kexec_booted"?

There seems to be no another way to check, I think your way is good.
Tryint to get it in kexec_get_rdsp_addr() earlier, you don't need to
judge specifically in efi_get_rsdp_addr() again.

> 
> >          if (!pa)
> >                  pa = bios_get_rsdp_addr();
> > 
> >          return pa;
> > }
> 
> -- 
> Jun'ichi Nomura, NEC Corporation / NEC Solution Innovators, Ltd.

  parent reply index

Thread overview: 90+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-22 11:03 [PATCH] " Junichi Nomura
2019-03-22 15:23 ` Borislav Petkov
2019-03-25  0:27   ` Junichi Nomura
2019-03-25  6:01     ` Dave Young
2019-03-25  6:19       ` Dave Young
2019-03-25  6:45         ` Kairui Song
2019-03-25  6:47         ` Junichi Nomura
2019-03-25  6:59           ` Dave Young
2019-03-25  8:27             ` [PATCH v2] " Junichi Nomura
2019-03-25  8:54               ` Boris Petkov
2019-03-25  9:25                 ` [PATCH v2] x86/boot: Don't try to search RSDP from EFI when kexec-booted Junichi Nomura
2019-03-25 10:15                 ` [PATCH v2] x86/boot: Use EFI setup data if provided Dave Young
2019-03-25 10:36                   ` Junichi Nomura
2019-03-25 11:16                     ` Dave Young
2019-03-25 12:01                     ` Borislav Petkov
2019-03-25 12:23                       ` Dave Young
2019-03-25 12:32                         ` Borislav Petkov
2019-03-25 23:10                           ` Junichi Nomura
2019-03-26 12:46                             ` Dave Young
2019-03-26 13:57                             ` Borislav Petkov
2019-03-27  1:48                               ` bhe
2019-03-27 12:14                                 ` Borislav Petkov
2019-03-28  4:17                                 ` Junichi Nomura
2019-03-28  6:26                                   ` Chao Fan
2019-03-28  6:43                                   ` bhe [this message]
2019-03-28  7:43                                     ` Junichi Nomura
2019-03-28 15:52                                       ` Borislav Petkov
2019-03-29  3:05                                         ` Junichi Nomura
2019-03-29  8:39                                           ` Borislav Petkov
2019-03-29  9:05                                             ` Chao Fan
2019-03-29  9:16                                               ` Borislav Petkov
2019-03-29  9:37                                                 ` Junichi Nomura
2019-03-29  9:44                                                   ` Chao Fan
2019-03-29  9:56                                                     ` Junichi Nomura
2019-03-29  7:20                                         ` [PATCH] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel Junichi Nomura
2019-03-29  7:49                                           ` bhe
2019-03-29  8:29                                           ` Chao Fan
2019-03-29  8:39                                             ` Junichi Nomura
2019-03-29  9:18                                               ` Chao Fan
2019-03-29  9:16                                             ` bhe
2019-03-29  9:20                                               ` Chao Fan
2019-04-01  0:08                                         ` [PATCH v2] " Junichi Nomura
2019-04-02  9:41                                           ` Chao Fan
2019-04-02  9:53                                             ` Junichi Nomura
2019-04-02 11:06                                               ` Chao Fan
2019-04-02 10:22                                                 ` Junichi Nomura
2019-04-02 12:03                                           ` Dave Young
2019-04-03  5:35                                             ` Chao Fan
2019-04-03  5:53                                               ` Dave Young
2019-04-03  6:39                                                 ` Dave Young
2019-04-03  7:30                                                   ` Chao Fan
2019-04-03  7:50                                                     ` bhe
2019-04-03  8:23                                                       ` Dave Young
2019-04-03  8:26                                                         ` Dave Young
2019-04-03 16:14                                                           ` Borislav Petkov
2019-04-04  1:02                                                             ` Chao Fan
2019-04-03  9:28                                                       ` Chao Fan
2019-04-03  7:21                                                 ` Chao Fan
2019-04-03  8:09                                                   ` Dave Young
2019-04-03  8:23                                                     ` Chao Fan
2019-04-03  9:02                                                       ` Chao Fan
2019-04-03  9:39                                                         ` Chao Fan
2019-04-04  1:23                                                         ` Junichi Nomura
2019-04-04  2:52                                                           ` Dave Young
2019-04-04  3:00                                                             ` bhe
2019-04-04  3:10                                                               ` bhe
2019-04-04  3:22                                                                 ` Dave Young
2019-04-04  6:41                                                                   ` Dave Young
2019-04-04  7:20                                                                     ` Chao Fan
2019-04-04  7:41                                                                       ` Dave Young
2019-04-04  7:48                                                                         ` Chao Fan
2019-04-04 12:22                                                                         ` Borislav Petkov
2019-04-04 14:08                                                                           ` Dave Young
2019-04-03  8:18                                                   ` Dave Young
2019-04-02 10:25                                         ` [PATCH v3] " Junichi Nomura
2019-04-04  7:32                                           ` Dave Young
2019-04-04 12:24                                             ` Borislav Petkov
2019-04-04 14:12                                               ` Dave Young
2019-04-04 14:41                                                 ` Borislav Petkov
2019-04-05  1:36                                                   ` Dave Young
2019-04-05  4:19                                             ` Junichi Nomura
2019-03-28 23:11                                       ` [PATCH v2] x86/boot: Use EFI setup data if provided bhe
2019-03-29  3:34                                         ` Junichi Nomura
2019-03-29  3:52                                           ` bhe
2019-03-29  5:16                                             ` Junichi Nomura
2019-03-25  7:27   ` [PATCH] " Baoquan He
2019-03-25  7:53     ` Borislav Petkov
2019-03-25  8:21       ` Baoquan He
2019-03-25  8:43         ` Thomas Gleixner
2019-03-25  9:03           ` Baoquan He

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190328064343.GA1877@MiWiFi-R3L-srv \
    --to=bhe@redhat.com \
    --cc=bp@alien8.de \
    --cc=dyoung@redhat.com \
    --cc=fanc.fnst@cn.fujitsu.com \
    --cc=j-nomura@ce.jp.nec.com \
    --cc=kasong@redhat.com \
    --cc=kexec@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org linux-kernel@archiver.kernel.org
	public-inbox-index lkml


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/ public-inbox