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authorAshish Kalra <ashish.kalra@amd.com>2024-01-26 07:11:19 +0300
committerBorislav Petkov (AMD) <bp@alien8.de>2024-01-29 22:34:18 +0300
commitf366a8dac1b8fef28a470d4e67b9843ebb8e2a1f (patch)
treeaa462024ab41a438123bd2be9090c497ead9783c /drivers/crypto
parenta867ad6b340f47b7333b80a54b8507fc2cd80aa4 (diff)
downloadlinux-f366a8dac1b8fef28a470d4e67b9843ebb8e2a1f.tar.xz
iommu/amd: Clean up RMP entries for IOMMU pages during SNP shutdown
Add a new IOMMU API interface amd_iommu_snp_disable() to transition IOMMU pages to Hypervisor state from Reclaim state after SNP_SHUTDOWN_EX command. Invoke this API from the CCP driver after SNP_SHUTDOWN_EX command. 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/20240126041126.1927228-20-michael.roth@amd.com
Diffstat (limited to 'drivers/crypto')
-rw-r--r--drivers/crypto/ccp/sev-dev.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index a70f8b11bccf..605c6bf88cf7 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -26,6 +26,7 @@
#include <linux/fs.h>
#include <linux/fs_struct.h>
#include <linux/psp.h>
+#include <linux/amd-iommu.h>
#include <asm/smp.h>
#include <asm/cacheflush.h>
@@ -1655,6 +1656,25 @@ static int __sev_snp_shutdown_locked(int *error)
return ret;
}
+ /*
+ * SNP_SHUTDOWN_EX with IOMMU_SNP_SHUTDOWN set to 1 disables SNP
+ * enforcement by the IOMMU and also transitions all pages
+ * associated with the IOMMU to the Reclaim state.
+ * Firmware was transitioning the IOMMU pages to Hypervisor state
+ * before version 1.53. But, accounting for the number of assigned
+ * 4kB pages in a 2M page was done incorrectly by not transitioning
+ * to the Reclaim state. This resulted in RMP #PF when later accessing
+ * the 2M page containing those pages during kexec boot. Hence, the
+ * firmware now transitions these pages to Reclaim state and hypervisor
+ * needs to transition these pages to shared state. SNP Firmware
+ * version 1.53 and above are needed for kexec boot.
+ */
+ ret = amd_iommu_snp_disable();
+ if (ret) {
+ dev_err(sev->dev, "SNP IOMMU shutdown failed\n");
+ return ret;
+ }
+
sev->snp_initialized = false;
dev_dbg(sev->dev, "SEV-SNP firmware shutdown\n");