From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx> MKTME keyid is assigned to guest TD. The memory controller encrypts guest TD memory with key id. Add helper functions to allocate/free MKTME keyid so that TDX KVM assign keyid. Also export MKTME global keyid that is used to encrypt TDX module and its memory. Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx> --- arch/x86/include/asm/tdx.h | 6 ++++++ arch/x86/virt/vmx/tdx.c | 33 ++++++++++++++++++++++++++++++++- 2 files changed, 38 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h index 9a8dc6afcb63..73bb472bd515 100644 --- a/arch/x86/include/asm/tdx.h +++ b/arch/x86/include/asm/tdx.h @@ -139,6 +139,9 @@ int tdx_detect(void); int tdx_init(void); bool platform_has_tdx(void); const struct tdsysinfo_struct *tdx_get_sysinfo(void); +u32 tdx_get_global_keyid(void); +int tdx_keyid_alloc(void); +void tdx_keyid_free(int keyid); #else static inline void tdx_detect_cpu(struct cpuinfo_x86 *c) { } static inline int tdx_detect(void) { return -ENODEV; } @@ -146,6 +149,9 @@ static inline int tdx_init(void) { return -ENODEV; } static inline bool platform_has_tdx(void) { return false; } struct tdsysinfo_struct; static inline const struct tdsysinfo_struct *tdx_get_sysinfo(void) { return NULL; } +static inline u32 tdx_get_global_keyid(void) { return 0; }; +static inline int tdx_keyid_alloc(void) { return -EOPNOTSUPP; } +static inline void tdx_keyid_free(int keyid) { } #endif /* CONFIG_INTEL_TDX_HOST */ #endif /* !__ASSEMBLY__ */ diff --git a/arch/x86/virt/vmx/tdx.c b/arch/x86/virt/vmx/tdx.c index e45f188479cb..d714106321d4 100644 --- a/arch/x86/virt/vmx/tdx.c +++ b/arch/x86/virt/vmx/tdx.c @@ -113,7 +113,13 @@ static int tdx_cmr_num; static struct tdsysinfo_struct tdx_sysinfo; /* TDX global KeyID to protect TDX metadata */ -static u32 tdx_global_keyid; +static u32 __read_mostly tdx_global_keyid; + +u32 tdx_get_global_keyid(void) +{ + return tdx_global_keyid; +} +EXPORT_SYMBOL_GPL(tdx_get_global_keyid); static bool enable_tdx_host; @@ -189,6 +195,31 @@ static void detect_seam(struct cpuinfo_x86 *c) detect_seam_ap(c); } +/* TDX KeyID pool */ +static DEFINE_IDA(tdx_keyid_pool); + +int tdx_keyid_alloc(void) +{ + if (WARN_ON_ONCE(!tdx_keyid_start || !tdx_keyid_num)) + return -EINVAL; + + /* The first keyID is reserved for the global key. */ + return ida_alloc_range(&tdx_keyid_pool, tdx_keyid_start + 1, + tdx_keyid_start + tdx_keyid_num - 1, + GFP_KERNEL); +} +EXPORT_SYMBOL_GPL(tdx_keyid_alloc); + +void tdx_keyid_free(int keyid) +{ + /* keyid = 0 is reserved. */ + if (!keyid || keyid <= 0) + return; + + ida_free(&tdx_keyid_pool, keyid); +} +EXPORT_SYMBOL_GPL(tdx_keyid_free); + static void detect_tdx_keyids_bsp(struct cpuinfo_x86 *c) { u64 keyid_part; -- 2.25.1