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Diffstat (limited to 'arch/x86/coco/tdx/tdx.c')
-rw-r--r--arch/x86/coco/tdx/tdx.c62
1 files changed, 60 insertions, 2 deletions
diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
index 3bd111d5e6a0..055300e08fb3 100644
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -19,9 +19,14 @@
#define TDX_GET_VEINFO 3
#define TDX_GET_REPORT 4
#define TDX_ACCEPT_PAGE 6
+#define TDX_WR 8
+
+/* TDCS fields. To be used by TDG.VM.WR and TDG.VM.RD module calls */
+#define TDCS_NOTIFY_ENABLES 0x9100000000000010
/* TDX hypercall Leaf IDs */
#define TDVMCALL_MAP_GPA 0x10001
+#define TDVMCALL_REPORT_FATAL_ERROR 0x10003
/* MMIO direction */
#define EPT_READ 0
@@ -37,6 +42,7 @@
#define VE_GET_PORT_NUM(e) ((e) >> 16)
#define VE_IS_IO_STRING(e) ((e) & BIT(4))
+#define ATTR_DEBUG BIT(0)
#define ATTR_SEPT_VE_DISABLE BIT(28)
/* TDX Module call error codes */
@@ -141,6 +147,41 @@ int tdx_mcall_get_report0(u8 *reportdata, u8 *tdreport)
}
EXPORT_SYMBOL_GPL(tdx_mcall_get_report0);
+static void __noreturn tdx_panic(const char *msg)
+{
+ struct tdx_hypercall_args args = {
+ .r10 = TDX_HYPERCALL_STANDARD,
+ .r11 = TDVMCALL_REPORT_FATAL_ERROR,
+ .r12 = 0, /* Error code: 0 is Panic */
+ };
+ union {
+ /* Define register order according to the GHCI */
+ struct { u64 r14, r15, rbx, rdi, rsi, r8, r9, rdx; };
+
+ char str[64];
+ } message;
+
+ /* VMM assumes '\0' in byte 65, if the message took all 64 bytes */
+ strncpy(message.str, msg, 64);
+
+ args.r8 = message.r8;
+ args.r9 = message.r9;
+ args.r14 = message.r14;
+ args.r15 = message.r15;
+ args.rdi = message.rdi;
+ args.rsi = message.rsi;
+ args.rbx = message.rbx;
+ args.rdx = message.rdx;
+
+ /*
+ * This hypercall should never return and it is not safe
+ * to keep the guest running. Call it forever if it
+ * happens to return.
+ */
+ while (1)
+ __tdx_hypercall(&args, 0);
+}
+
static void tdx_parse_tdinfo(u64 *cc_mask)
{
struct tdx_module_output out;
@@ -172,8 +213,15 @@ static void tdx_parse_tdinfo(u64 *cc_mask)
* TD-private memory. Only VMM-shared memory (MMIO) will #VE.
*/
td_attr = out.rdx;
- if (!(td_attr & ATTR_SEPT_VE_DISABLE))
- panic("TD misconfiguration: SEPT_VE_DISABLE attibute must be set.\n");
+ if (!(td_attr & ATTR_SEPT_VE_DISABLE)) {
+ const char *msg = "TD misconfiguration: SEPT_VE_DISABLE attribute must be set.";
+
+ /* Relax SEPT_VE_DISABLE check for debug TD. */
+ if (td_attr & ATTR_DEBUG)
+ pr_warn("%s\n", msg);
+ else
+ tdx_panic(msg);
+ }
}
/*
@@ -617,6 +665,11 @@ static int virt_exception_user(struct pt_regs *regs, struct ve_info *ve)
}
}
+static inline bool is_private_gpa(u64 gpa)
+{
+ return gpa == cc_mkenc(gpa);
+}
+
/*
* Handle the kernel #VE.
*
@@ -635,6 +688,8 @@ static int virt_exception_kernel(struct pt_regs *regs, struct ve_info *ve)
case EXIT_REASON_CPUID:
return handle_cpuid(regs, ve);
case EXIT_REASON_EPT_VIOLATION:
+ if (is_private_gpa(ve->gpa))
+ panic("Unexpected EPT-violation on private memory.");
return handle_mmio(regs, ve);
case EXIT_REASON_IO_INSTRUCTION:
return handle_io(regs, ve);
@@ -801,6 +856,9 @@ void __init tdx_early_init(void)
tdx_parse_tdinfo(&cc_mask);
cc_set_mask(cc_mask);
+ /* Kernel does not use NOTIFY_ENABLES and does not need random #VEs */
+ tdx_module_call(TDX_WR, 0, TDCS_NOTIFY_ENABLES, 0, -1ULL, NULL);
+
/*
* All bits above GPA width are reserved and kernel treats shared bit
* as flag, not as part of physical address.