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authorAshish Kalra <ashish.kalra@amd.com>2024-01-26 07:11:20 +0300
committerBorislav Petkov (AMD) <bp@alien8.de>2024-01-29 22:34:19 +0300
commit8ef979584ea86c247b768f4420148721a842835f (patch)
tree7b8bb8ca5c21d1fd4cac6a95a889fc5891f51963 /arch/x86/kernel/sev.c
parentf366a8dac1b8fef28a470d4e67b9843ebb8e2a1f (diff)
downloadlinux-8ef979584ea86c247b768f4420148721a842835f.tar.xz
crypto: ccp: Add panic notifier for SEV/SNP firmware shutdown on kdump
Add a kdump safe version of sev_firmware_shutdown() and register it as a crash_kexec_post_notifier so it will be invoked during panic/crash to do SEV/SNP shutdown. This is required for transitioning all IOMMU pages to reclaim/hypervisor state, otherwise re-init of IOMMU pages during crashdump kernel boot fails and panics the crashdump kernel. This panic notifier runs in atomic context, hence it ensures not to acquire any locks/mutexes and polls for PSP command completion instead of depending on PSP command completion interrupt. [ mdr: Remove use of "we" in comments. ] Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20240126041126.1927228-21-michael.roth@amd.com
Diffstat (limited to 'arch/x86/kernel/sev.c')
-rw-r--r--arch/x86/kernel/sev.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index 1ec753331524..002af6c30601 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -2265,3 +2265,13 @@ static int __init snp_init_platform_device(void)
return 0;
}
device_initcall(snp_init_platform_device);
+
+void kdump_sev_callback(void)
+{
+ /*
+ * Do wbinvd() on remote CPUs when SNP is enabled in order to
+ * safely do SNP_SHUTDOWN on the local CPU.
+ */
+ if (cpu_feature_enabled(X86_FEATURE_SEV_SNP))
+ wbinvd();
+}