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kdump-lib.sh: add extra 64M to default crashkernel if sme/sev is active 

It's reported that kdump kernel failed to boot and can't dump vmcore
when crashkernel=192M and SME/SEV is active.

This is because swiotlb will be enabled and reserves 64M memory by
default on system with SME/SEV enabled. Then kdump kernel will be out of
memory after taking 64M away for swiotlb init.

So here add extra 64M memory to default crashkernel value so that kdump
kernel can function well as before. When doing that, search journalctl
for the "Memory Encryption Features active: AMD" to check if SME or SEV
is active. This line of log is printed out in kernel function as below
and the type SME is mutual exclusive with type SEV.
  ***:
  arch/x86/mm/mem_encrypt.c:print_mem_encrypt_feature_info()

Note:
1) The conditional check is relying on journalctl log because I didn't
   find available system interface to check if SEV is active. Even
   though we can check if SME is active via /proc/cpuinfo. For
   consistency, I take the same check for both SME and SEV by searching
   journalctl.

2) The conditional check is relying on journalctl log, means it won't
   work for crashkernel setting in anoconda because the installation
   kernel doesn't have the SME/SEV setting. So customer need manually
   run 'kdumpctl reset-crashkernel' to reset crashkernel to add the
   extra 64M after OS installation.

3) We need watch the line of log printing in
   print_mem_encrypt_feature_info() in kernel just in case people may
   change it in the future.

Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Philipp Rudo <prudo@redhat.com>
This commit is contained in:
Baoquan He 2023-09-21 18:01:02 +08:00 committed by Coiby Xu
parent 3d253ab811
commit 4841bc6a6d
1 changed files with 8 additions and 3 deletions
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11
kdump-lib.sh
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@ -38,6 +38,11 @@ is_aws_aarch64()
[[ "$(lscpu | grep "BIOS Model name")" =~ "AWS Graviton" ]]
}
is_sme_or_sev_active()
{
journalctl -q --dmesg --grep "^Memory Encryption Features active: AMD (SME|SEV)$" >/dev/null 2>&1
}
is_squash_available()
{
local _version kmodule
@ -1001,6 +1006,7 @@ _crashkernel_add()
kdump_get_arch_recommend_crashkernel()
{
local _arch _ck_cmdline _dump_mode
local _delta=0
if [[ -z "$1" ]]; then
if is_fadump_capable; then
@ -1016,9 +1022,9 @@ kdump_get_arch_recommend_crashkernel()
if [[ $_arch == "x86_64" ]] || [[ $_arch == "s390x" ]]; then
_ck_cmdline="1G-4G:192M,4G-64G:256M,64G-:512M"
is_sme_or_sev_active && ((_delta += 64))
elif [[ $_arch == "aarch64" ]]; then
local _running_kernel
local _delta=0
# Base line for 4K variant kernel. The formula is based on x86 plus extra = 64M
_ck_cmdline="1G-4G:256M,4G-64G:320M,64G-:576M"
@ -1042,7 +1048,6 @@ kdump_get_arch_recommend_crashkernel()
#4k kernel, mlx5 consumes extra 124M memory, and choose 150M
has_mlx5 && ((_delta += 150))
fi
_ck_cmdline=$(_crashkernel_add "$_ck_cmdline" "${_delta}M")
elif [[ $_arch == "ppc64le" ]]; then
if [[ $_dump_mode == "fadump" ]]; then
_ck_cmdline="4G-16G:768M,16G-64G:1G,64G-128G:2G,128G-1T:4G,1T-2T:6G,2T-4T:12G,4T-8T:20G,8T-16T:36G,16T-32T:64G,32T-64T:128G,64T-:180G"
@ -1051,7 +1056,7 @@ kdump_get_arch_recommend_crashkernel()
fi
fi
echo -n "$_ck_cmdline"
echo -n "$(_crashkernel_add "$_ck_cmdline" "${_delta}M")"
}
# return recommended size based on current system RAM size