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Message-ID: <20230530150106.2703849-1-ross.lagerwall@citrix.com>
Date: Tue, 30 May 2023 16:01:06 +0100
From: Ross Lagerwall <ross.lagerwall@...rix.com>
To: <linux-kernel@...r.kernel.org>, <xen-devel@...ts.xenproject.org>
CC: Jan Beulich <jbeulich@...e.com>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
Dave Hansen <dave.hansen@...ux.intel.com>, <x86@...nel.org>,
Juergen Gross <jgross@...e.com>,
Boris Ostrovsky <boris.ostrovsky@...cle.com>,
Peter Jones <pjones@...hat.com>,
Konrad Rzeszutek Wilk <konrad@...nel.org>,
"Ross Lagerwall" <ross.lagerwall@...rix.com>
Subject: [PATCH v2] iscsi_ibft: Fix finding the iBFT under Xen Dom 0
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@...rix.com>
---
In v2:
* Fix style issue
* Make added e820 entry conditional on ISCSI_IBFT_FIND
arch/x86/kernel/setup.c | 2 +-
arch/x86/xen/setup.c | 27 ++++++++++++++++++---------
drivers/firmware/iscsi_ibft_find.c | 24 +++++++++++++++++-------
3 files changed, 36 insertions(+), 17 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..07c7039bdd66 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -764,17 +764,26 @@ char * __init xen_memory_setup(void)
BUG_ON(memmap.nr_entries == 0);
xen_e820_table.nr_entries = memmap.nr_entries;
- /*
- * Xen won't allow a 1:1 mapping to be created to UNUSABLE
- * regions, so if we're using the machine memory map leave the
- * region as RAM as it is in the pseudo-physical map.
- *
- * UNUSABLE regions in domUs are not handled and will need
- * a patch in the future.
- */
- if (xen_initial_domain())
+ if (xen_initial_domain()) {
+ /*
+ * Xen won't allow a 1:1 mapping to be created to UNUSABLE
+ * regions, so if we're using the machine memory map leave the
+ * region as RAM as it is in the pseudo-physical map.
+ *
+ * UNUSABLE regions in domUs are not handled and will need
+ * a patch in the future.
+ */
xen_ignore_unusable();
+#ifdef CONFIG_ISCSI_IBFT_FIND
+ /* 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++;
+#endif
+ }
+
/* 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);
}
--
2.31.1
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