From: Fiona Ebner <f.ebner@proxmox.com>
To: pve-devel@lists.proxmox.com
Subject: [pve-devel] [PATCH edk2-firmware] add patch to work around older guest kernel bug
Date: Mon, 5 Jun 2023 09:43:50 +0200 [thread overview]
Message-ID: <20230605074350.98641-1-f.ebner@proxmox.com> (raw)
by limiting the phys-bits to 46 instead of 47. On Ubuntu 18.04 with
kernel 4.15, using 47 leads to a strange issue where initialization of
VirtIO devices would fail.
Reported in the community forum:
https://forum.proxmox.com/threads/127410/
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
---
...latformInitLib-limit-phys-bits-to-46.patch | 46 +++++++++++++++++++
debian/patches/series | 1 +
2 files changed, 47 insertions(+)
create mode 100644 debian/patches/0001-OvmfPkg-PlatformInitLib-limit-phys-bits-to-46.patch
diff --git a/debian/patches/0001-OvmfPkg-PlatformInitLib-limit-phys-bits-to-46.patch b/debian/patches/0001-OvmfPkg-PlatformInitLib-limit-phys-bits-to-46.patch
new file mode 100644
index 0000000..7f49a14
--- /dev/null
+++ b/debian/patches/0001-OvmfPkg-PlatformInitLib-limit-phys-bits-to-46.patch
@@ -0,0 +1,46 @@
+From 89a12f2a42b989e7925b4a71e503209971eaa271 Mon Sep 17 00:00:00 2001
+From: Gerd Hoffmann <kraxel@redhat.com>
+Date: Thu, 1 Jun 2023 09:57:31 +0200
+Subject: [PATCH] OvmfPkg/PlatformInitLib: limit phys-bits to 46.
+
+Older linux kernels have problems with phys-bits larger than 46,
+ubuntu 18.04 (kernel 4.15) has been reported to be affected.
+
+Reduce phys-bits limit from 47 to 46.
+
+Reported-by: Fiona Ebner <f.ebner@proxmox.com>
+Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
+---
+ OvmfPkg/Library/PlatformInitLib/MemDetect.c | 9 ++++++---
+ 1 file changed, 6 insertions(+), 3 deletions(-)
+
+diff --git a/OvmfPkg/Library/PlatformInitLib/MemDetect.c b/OvmfPkg/Library/PlatformInitLib/MemDetect.c
+index 38cece9173..4d0522ce22 100644
+--- a/OvmfPkg/Library/PlatformInitLib/MemDetect.c
++++ b/OvmfPkg/Library/PlatformInitLib/MemDetect.c
+@@ -657,16 +657,19 @@ PlatformAddressWidthFromCpuid (
+ ));
+
+ if (Valid) {
+- if (PhysBits > 47) {
++ if (PhysBits > 46) {
+ /*
+ * Avoid 5-level paging altogether for now, which limits
+ * PhysBits to 48. Also avoid using address bit 48, due to sign
+ * extension we can't identity-map these addresses (and lots of
+ * places in edk2 assume we have everything identity-mapped).
+ * So the actual limit is 47.
++ *
++ * Also some older linux kernels apparently have problems handling
++ * phys-bits > 46 correctly, so use that as limit.
+ */
+- DEBUG ((DEBUG_INFO, "%a: limit PhysBits to 47 (avoid 5-level paging)\n", __func__));
+- PhysBits = 47;
++ DEBUG ((DEBUG_INFO, "%a: limit PhysBits to 46 (avoid 5-level paging)\n", __func__));
++ PhysBits = 46;
+ }
+
+ if (!Page1GSupport && (PhysBits > 40)) {
+--
+2.39.2
+
diff --git a/debian/patches/series b/debian/patches/series
index f1ec614..a9ee2be 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -2,3 +2,4 @@ no-stack-protector-all-archs.diff
brotlicompress-disable.diff
x64-baseline-abi.patch
Revert-ArmVirtPkg-make-EFI_LOADER_DATA-non-executabl.patch
+0001-OvmfPkg-PlatformInitLib-limit-phys-bits-to-46.patch
--
2.39.2
next reply other threads:[~2023-06-05 7:44 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-05 7:43 Fiona Ebner [this message]
2023-06-06 14:26 ` [pve-devel] applied: " Thomas Lamprecht
2023-06-07 9:04 ` Fiona Ebner
2023-06-07 10:12 ` Fiona Ebner
2023-06-07 10:25 ` Thomas Lamprecht
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