| Message ID | 20230524160558.3686226-1-ross.lagerwall@citrix.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | iscsi_ibft: Fix finding the iBFT under Xen Dom 0 | expand |
On 24.05.2023 18:05, Ross Lagerwall wrote: > --- a/arch/x86/xen/setup.c > +++ b/arch/x86/xen/setup.c > @@ -772,8 +772,14 @@ char * __init xen_memory_setup(void) > * UNUSABLE regions in domUs are not handled and will need > * a patch in the future. > */ I think this comment now wants to move ... > - if (xen_initial_domain()) > + if (xen_initial_domain()) { ... here. And then likely you want a blank line ... > xen_ignore_unusable(); ... here. > + /* Reserve 0.5 MiB to 1 MiB region so iBFT can be found */ > + xen_e820_table.entries[xen_e820_table.nr_entries].addr = 0x80000; > + xen_e820_table.entries[xen_e820_table.nr_entries].size = 0x80000; > + xen_e820_table.entries[xen_e820_table.nr_entries].type = E820_TYPE_RESERVED; > + xen_e820_table.nr_entries++; Surely this can be omitted when !CONFIG_ISCSI_IBFT_FIND? Jan
> From: Jan Beulich <jbeulich@suse.com> > Sent: Thursday, May 25, 2023 10:31 AM > To: Ross Lagerwall <ross.lagerwall@citrix.com> > Cc: Thomas Gleixner <tglx@linutronix.de>; Ingo Molnar <mingo@redhat.com>; Borislav Petkov <bp@alien8.de>; Dave Hansen <dave.hansen@linux.intel.com>; x86@kernel.org <x86@kernel.org>; Juergen Gross <jgross@suse.com>; Boris Ostrovsky <boris.ostrovsky@oracle.com>; Peter Jones <pjones@redhat.com>; Konrad Rzeszutek Wilk <konrad@kernel.org>; linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>; xen-devel@lists.xenproject.org <xen-devel@lists.xenproject.org> > Subject: Re: [PATCH] iscsi_ibft: Fix finding the iBFT under Xen Dom 0 > > [CAUTION - EXTERNAL EMAIL] DO NOT reply, click links, or open attachments unless you have verified the sender and know the content is safe. > > On 24.05.2023 18:05, Ross Lagerwall wrote: > > --- a/arch/x86/xen/setup.c > > +++ b/arch/x86/xen/setup.c > > @@ -772,8 +772,14 @@ char * __init xen_memory_setup(void) > > * UNUSABLE regions in domUs are not handled and will need > > * a patch in the future. > > */ > > I think this comment now wants to move ... > > > - if (xen_initial_domain()) > > + if (xen_initial_domain()) { > > ... here. And then likely you want a blank line ... > > > xen_ignore_unusable(); > > ... here. OK > > > + /* Reserve 0.5 MiB to 1 MiB region so iBFT can be found */ > > + xen_e820_table.entries[xen_e820_table.nr_entries].addr = 0x80000; > > + xen_e820_table.entries[xen_e820_table.nr_entries].size = 0x80000; > > + xen_e820_table.entries[xen_e820_table.nr_entries].type = E820_TYPE_RESERVED; > > + xen_e820_table.nr_entries++; > > Surely this can be omitted when !CONFIG_ISCSI_IBFT_FIND? > Yes, good point. I will fix that. Thanks, Ross
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 16babff771bd..616b80507abd 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -796,7 +796,6 @@ static void __init early_reserve_memory(void) memblock_x86_reserve_range_setup_data(); - reserve_ibft_region(); reserve_bios_regions(); trim_snb_memory(); } @@ -1032,6 +1031,7 @@ void __init setup_arch(char **cmdline_p) if (efi_enabled(EFI_BOOT)) efi_init(); + reserve_ibft_region(); dmi_setup(); /* diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index c2be3efb2ba0..daab59df3b99 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -772,8 +772,14 @@ char * __init xen_memory_setup(void) * UNUSABLE regions in domUs are not handled and will need * a patch in the future. */ - if (xen_initial_domain()) + if (xen_initial_domain()) { xen_ignore_unusable(); + /* Reserve 0.5 MiB to 1 MiB region so iBFT can be found */ + xen_e820_table.entries[xen_e820_table.nr_entries].addr = 0x80000; + xen_e820_table.entries[xen_e820_table.nr_entries].size = 0x80000; + xen_e820_table.entries[xen_e820_table.nr_entries].type = E820_TYPE_RESERVED; + xen_e820_table.nr_entries++; + } /* Make sure the Xen-supplied memory map is well-ordered. */ e820__update_table(&xen_e820_table); diff --git a/drivers/firmware/iscsi_ibft_find.c b/drivers/firmware/iscsi_ibft_find.c index 94b49ccd23ac..e3c1449987dd 100644 --- a/drivers/firmware/iscsi_ibft_find.c +++ b/drivers/firmware/iscsi_ibft_find.c @@ -52,9 +52,9 @@ static const struct { */ void __init reserve_ibft_region(void) { - unsigned long pos; + unsigned long pos, virt_pos = 0; unsigned int len = 0; - void *virt; + void *virt = NULL; int i; ibft_phys_addr = 0; @@ -70,13 +70,20 @@ void __init reserve_ibft_region(void) * so skip that area */ if (pos == VGA_MEM) pos += VGA_SIZE; - virt = isa_bus_to_virt(pos); + + /* Map page by page */ + if (offset_in_page(pos) == 0) { + if (virt) + early_memunmap(virt, PAGE_SIZE); + virt = early_memremap_ro(pos, PAGE_SIZE); + virt_pos = pos; + } for (i = 0; i < ARRAY_SIZE(ibft_signs); i++) { - if (memcmp(virt, ibft_signs[i].sign, IBFT_SIGN_LEN) == - 0) { + if (memcmp(virt + (pos - virt_pos), ibft_signs[i].sign, + IBFT_SIGN_LEN) == 0) { unsigned long *addr = - (unsigned long *)isa_bus_to_virt(pos + 4); + (unsigned long *)(virt + pos - virt_pos + 4); len = *addr; /* if the length of the table extends past 1M, * the table cannot be valid. */ @@ -84,9 +91,12 @@ void __init reserve_ibft_region(void) ibft_phys_addr = pos; memblock_reserve(ibft_phys_addr, PAGE_ALIGN(len)); pr_info("iBFT found at %pa.\n", &ibft_phys_addr); - return; + goto out; } } } } + +out: + early_memunmap(virt, PAGE_SIZE); }
Since firmware doesn't indicate the iBFT in the E820, add a reserved region so that it gets identity mapped when running as Dom 0 so that it is possible to search for it. Move the call to reserve_ibft_region() later so that it is called after the Xen identity mapping adjustments are applied. Finally, instead of using isa_bus_to_virt() which doesn't do the right thing under Xen, use early_memremap() like the dmi_scan code does. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> --- It tested this to work under Xen and native Linux. arch/x86/kernel/setup.c | 2 +- arch/x86/xen/setup.c | 8 +++++++- drivers/firmware/iscsi_ibft_find.c | 24 +++++++++++++++++------- 3 files changed, 25 insertions(+), 9 deletions(-)