diff options
Diffstat (limited to 'arch/x86/coco/tdx/tdx.c')
| -rw-r--r-- | arch/x86/coco/tdx/tdx.c | 65 |
1 files changed, 58 insertions, 7 deletions
diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c index 928dcf7a20d9..cfd4c95b9f04 100644 --- a/arch/x86/coco/tdx/tdx.c +++ b/arch/x86/coco/tdx/tdx.c @@ -5,6 +5,8 @@ #define pr_fmt(fmt) "tdx: " fmt #include <linux/cpufeature.h> +#include <linux/export.h> +#include <linux/io.h> #include <asm/coco.h> #include <asm/tdx.h> #include <asm/vmx.h> @@ -15,6 +17,7 @@ /* TDX module Call Leaf IDs */ #define TDX_GET_INFO 1 #define TDX_GET_VEINFO 3 +#define TDX_GET_REPORT 4 #define TDX_ACCEPT_PAGE 6 /* TDX hypercall Leaf IDs */ @@ -34,6 +37,14 @@ #define VE_GET_PORT_NUM(e) ((e) >> 16) #define VE_IS_IO_STRING(e) ((e) & BIT(4)) +#define ATTR_SEPT_VE_DISABLE BIT(28) + +/* TDX Module call error codes */ +#define TDCALL_RETURN_CODE(a) ((a) >> 32) +#define TDCALL_INVALID_OPERAND 0xc0000100 + +#define TDREPORT_SUBTYPE_0 0 + /* * Wrapper for standard use of __tdx_hypercall with no output aside from * return code. @@ -98,10 +109,42 @@ static inline void tdx_module_call(u64 fn, u64 rcx, u64 rdx, u64 r8, u64 r9, panic("TDCALL %lld failed (Buggy TDX module!)\n", fn); } -static u64 get_cc_mask(void) +/** + * tdx_mcall_get_report0() - Wrapper to get TDREPORT0 (a.k.a. TDREPORT + * subtype 0) using TDG.MR.REPORT TDCALL. + * @reportdata: Address of the input buffer which contains user-defined + * REPORTDATA to be included into TDREPORT. + * @tdreport: Address of the output buffer to store TDREPORT. + * + * Refer to section titled "TDG.MR.REPORT leaf" in the TDX Module + * v1.0 specification for more information on TDG.MR.REPORT TDCALL. + * It is used in the TDX guest driver module to get the TDREPORT0. + * + * Return 0 on success, -EINVAL for invalid operands, or -EIO on + * other TDCALL failures. + */ +int tdx_mcall_get_report0(u8 *reportdata, u8 *tdreport) +{ + u64 ret; + + ret = __tdx_module_call(TDX_GET_REPORT, virt_to_phys(tdreport), + virt_to_phys(reportdata), TDREPORT_SUBTYPE_0, + 0, NULL); + if (ret) { + if (TDCALL_RETURN_CODE(ret) == TDCALL_INVALID_OPERAND) + return -EINVAL; + return -EIO; + } + + return 0; +} +EXPORT_SYMBOL_GPL(tdx_mcall_get_report0); + +static void tdx_parse_tdinfo(u64 *cc_mask) { struct tdx_module_output out; unsigned int gpa_width; + u64 td_attr; /* * TDINFO TDX module call is used to get the TD execution environment @@ -109,19 +152,27 @@ static u64 get_cc_mask(void) * information, etc. More details about the ABI can be found in TDX * Guest-Host-Communication Interface (GHCI), section 2.4.2 TDCALL * [TDG.VP.INFO]. + */ + tdx_module_call(TDX_GET_INFO, 0, 0, 0, 0, &out); + + /* + * The highest bit of a guest physical address is the "sharing" bit. + * Set it for shared pages and clear it for private pages. * * The GPA width that comes out of this call is critical. TDX guests * can not meaningfully run without it. */ - tdx_module_call(TDX_GET_INFO, 0, 0, 0, 0, &out); - gpa_width = out.rcx & GENMASK(5, 0); + *cc_mask = BIT_ULL(gpa_width - 1); /* - * The highest bit of a guest physical address is the "sharing" bit. - * Set it for shared pages and clear it for private pages. + * The kernel can not handle #VE's when accessing normal kernel + * memory. Ensure that no #VE will be delivered for accesses to + * TD-private memory. Only VMM-shared memory (MMIO) will #VE. */ - return BIT_ULL(gpa_width - 1); + td_attr = out.rdx; + if (!(td_attr & ATTR_SEPT_VE_DISABLE)) + panic("TD misconfiguration: SEPT_VE_DISABLE attibute must be set.\n"); } /* @@ -758,7 +809,7 @@ void __init tdx_early_init(void) setup_force_cpu_cap(X86_FEATURE_TDX_GUEST); cc_set_vendor(CC_VENDOR_INTEL); - cc_mask = get_cc_mask(); + tdx_parse_tdinfo(&cc_mask); cc_set_mask(cc_mask); /* |