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(-)
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(-)
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);
}
--
2.31.1On 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
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