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x86/virt/tdx: Configure TDX module with the TDMRs and global KeyID
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The TDX module uses a private KeyID as the "global KeyID" for mapping
things like the PAMT and other TDX metadata.  This KeyID has already
been reserved when detecting TDX during the kernel early boot.

Now that the "TD Memory Regions" (TDMRs) are fully built, pass them to
the TDX module together with the global KeyID.

Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Isaku Yamahata <isaku.yamahata@intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Yuan Yao <yuan.yao@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20231208170740.53979-13-dave.hansen%40intel.com
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Kai Huang authored and Dave Hansen committed Dec 8, 2023
1 parent dde3b60 commit 554ce1c
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Showing 2 changed files with 44 additions and 1 deletion.
43 changes: 42 additions & 1 deletion arch/x86/virt/vmx/tdx/tdx.c
Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,8 @@
#include <linux/pfn.h>
#include <linux/align.h>
#include <linux/sort.h>
#include <linux/log2.h>
#include <asm/page.h>
#include <asm/msr-index.h>
#include <asm/msr.h>
#include <asm/cpufeature.h>
Expand Down Expand Up @@ -892,6 +894,41 @@ static int construct_tdmrs(struct list_head *tmb_list,
return ret;
}

static int config_tdx_module(struct tdmr_info_list *tdmr_list, u64 global_keyid)
{
struct tdx_module_args args = {};
u64 *tdmr_pa_array;
size_t array_sz;
int i, ret;

/*
* TDMRs are passed to the TDX module via an array of physical
* addresses of each TDMR. The array itself also has certain
* alignment requirement.
*/
array_sz = tdmr_list->nr_consumed_tdmrs * sizeof(u64);
array_sz = roundup_pow_of_two(array_sz);
if (array_sz < TDMR_INFO_PA_ARRAY_ALIGNMENT)
array_sz = TDMR_INFO_PA_ARRAY_ALIGNMENT;

tdmr_pa_array = kzalloc(array_sz, GFP_KERNEL);
if (!tdmr_pa_array)
return -ENOMEM;

for (i = 0; i < tdmr_list->nr_consumed_tdmrs; i++)
tdmr_pa_array[i] = __pa(tdmr_entry(tdmr_list, i));

args.rcx = __pa(tdmr_pa_array);
args.rdx = tdmr_list->nr_consumed_tdmrs;
args.r8 = global_keyid;
ret = seamcall_prerr(TDH_SYS_CONFIG, &args);

/* Free the array as it is not required anymore. */
kfree(tdmr_pa_array);

return ret;
}

static int init_tdx_module(void)
{
struct tdx_tdmr_sysinfo tdmr_sysinfo;
Expand Down Expand Up @@ -927,10 +964,14 @@ static int init_tdx_module(void)
if (ret)
goto err_free_tdmrs;

/* Pass the TDMRs and the global KeyID to the TDX module */
ret = config_tdx_module(&tdx_tdmr_list, tdx_global_keyid);
if (ret)
goto err_free_pamts;

/*
* TODO:
*
* - Configure the TDMRs and the global KeyID to the TDX module.
* - Configure the global KeyID on all packages.
* - Initialize all TDMRs.
*
Expand Down
2 changes: 2 additions & 0 deletions arch/x86/virt/vmx/tdx/tdx.h
Original file line number Diff line number Diff line change
Expand Up @@ -17,6 +17,7 @@
#define TDH_SYS_INIT 33
#define TDH_SYS_RD 34
#define TDH_SYS_LP_INIT 35
#define TDH_SYS_CONFIG 45

/*
* Global scope metadata field ID.
Expand Down Expand Up @@ -53,6 +54,7 @@ struct tdmr_reserved_area {
} __packed;

#define TDMR_INFO_ALIGNMENT 512
#define TDMR_INFO_PA_ARRAY_ALIGNMENT 512

struct tdmr_info {
u64 base;
Expand Down

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