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Subject[PATCH v5 18/22] x86/virt/tdx: Configure TDX module with TDMRs and global KeyID
Date
After the TDX-usable memory regions are constructed in an array of TDMRs
and the global KeyID is reserved, configure them to the TDX module using
TDH.SYS.CONFIG SEAMCALL. TDH.SYS.CONFIG can only be called once and can
be done on any logical cpu.

Signed-off-by: Kai Huang <kai.huang@intel.com>
---
arch/x86/virt/vmx/tdx/tdx.c | 38 +++++++++++++++++++++++++++++++++++++
arch/x86/virt/vmx/tdx/tdx.h | 2 ++
2 files changed, 40 insertions(+)

diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
index df87a9f9ee24..06e26379b632 100644
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -18,6 +18,7 @@
#include <linux/sizes.h>
#include <linux/memblock.h>
#include <linux/gfp.h>
+#include <linux/slab.h>
#include <linux/align.h>
#include <linux/sort.h>
#include <asm/cpufeatures.h>
@@ -932,6 +933,37 @@ static int construct_tdmrs_memeblock(struct tdmr_info *tdmr_array,
return ret;
}

+static int config_tdx_module(struct tdmr_info *tdmr_array, int tdmr_num,
+ u64 global_keyid)
+{
+ u64 *tdmr_pa_array;
+ int i, array_sz;
+ u64 ret;
+
+ /*
+ * TDMR_INFO entries are configured to the TDX module via an
+ * array of the physical address of each TDMR_INFO. TDX module
+ * requires the array itself to be 512-byte aligned. Round up
+ * the array size to 512-byte aligned so the buffer allocated
+ * by kzalloc() will meet the alignment requirement.
+ */
+ array_sz = ALIGN(tdmr_num * sizeof(u64), TDMR_INFO_PA_ARRAY_ALIGNMENT);
+ tdmr_pa_array = kzalloc(array_sz, GFP_KERNEL);
+ if (!tdmr_pa_array)
+ return -ENOMEM;
+
+ for (i = 0; i < tdmr_num; i++)
+ tdmr_pa_array[i] = __pa(tdmr_array_entry(tdmr_array, i));
+
+ ret = seamcall(TDH_SYS_CONFIG, __pa(tdmr_pa_array), tdmr_num,
+ global_keyid, 0, NULL);
+
+ /* Free the array as it is not required any more. */
+ kfree(tdmr_pa_array);
+
+ return ret ? -EFAULT : 0;
+}
+
/*
* Detect and initialize the TDX module.
*
@@ -999,11 +1031,17 @@ static int init_tdx_module(void)
*/
tdx_global_keyid = tdx_keyid_start;

+ /* Pass the TDMRs and the global KeyID to the TDX module */
+ ret = config_tdx_module(tdmr_array, tdmr_num, tdx_global_keyid);
+ if (ret)
+ goto out_free_pamts;
+
/*
* Return -EINVAL until all steps of TDX module initialization
* process are done.
*/
ret = -EINVAL;
+out_free_pamts:
if (ret)
tdmrs_free_pamt_all(tdmr_array, tdmr_num);
else
diff --git a/arch/x86/virt/vmx/tdx/tdx.h b/arch/x86/virt/vmx/tdx/tdx.h
index 55d6c69ab900..b9bc499b965b 100644
--- a/arch/x86/virt/vmx/tdx/tdx.h
+++ b/arch/x86/virt/vmx/tdx/tdx.h
@@ -53,6 +53,7 @@
#define TDH_SYS_INIT 33
#define TDH_SYS_LP_INIT 35
#define TDH_SYS_LP_SHUTDOWN 44
+#define TDH_SYS_CONFIG 45

struct cmr_info {
u64 base;
@@ -120,6 +121,7 @@ struct tdmr_reserved_area {
} __packed;

#define TDMR_INFO_ALIGNMENT 512
+#define TDMR_INFO_PA_ARRAY_ALIGNMENT 512

struct tdmr_info {
u64 base;
--
2.36.1
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