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-rw-r--r--arch/x86/coco/tdx/tdx.c161
1 files changed, 116 insertions, 45 deletions
diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
index f3c75809fe..cf1f13c821 100644
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -39,7 +39,7 @@
#define TDREPORT_SUBTYPE_0 0
/* Called from __tdx_hypercall() for unrecoverable failure */
-noinstr void __tdx_hypercall_failed(void)
+noinstr void __noreturn __tdx_hypercall_failed(void)
{
instrumentation_begin();
panic("TDVMCALL failed. TDX module bug?");
@@ -49,7 +49,7 @@ noinstr void __tdx_hypercall_failed(void)
long tdx_kvm_hypercall(unsigned int nr, unsigned long p1, unsigned long p2,
unsigned long p3, unsigned long p4)
{
- struct tdx_hypercall_args args = {
+ struct tdx_module_args args = {
.r10 = nr,
.r11 = p1,
.r12 = p2,
@@ -67,10 +67,9 @@ EXPORT_SYMBOL_GPL(tdx_kvm_hypercall);
* should only be used for calls that have no legitimate reason to fail
* or where the kernel can not survive the call failing.
*/
-static inline void tdx_module_call(u64 fn, u64 rcx, u64 rdx, u64 r8, u64 r9,
- struct tdx_module_output *out)
+static inline void tdcall(u64 fn, struct tdx_module_args *args)
{
- if (__tdx_module_call(fn, rcx, rdx, r8, r9, out))
+ if (__tdcall_ret(fn, args))
panic("TDCALL %lld failed (Buggy TDX module!)\n", fn);
}
@@ -90,11 +89,14 @@ static inline void tdx_module_call(u64 fn, u64 rcx, u64 rdx, u64 r8, u64 r9,
*/
int tdx_mcall_get_report0(u8 *reportdata, u8 *tdreport)
{
+ struct tdx_module_args args = {
+ .rcx = virt_to_phys(tdreport),
+ .rdx = virt_to_phys(reportdata),
+ .r8 = TDREPORT_SUBTYPE_0,
+ };
u64 ret;
- ret = __tdx_module_call(TDX_GET_REPORT, virt_to_phys(tdreport),
- virt_to_phys(reportdata), TDREPORT_SUBTYPE_0,
- 0, NULL);
+ ret = __tdcall(TDG_MR_REPORT, &args);
if (ret) {
if (TDCALL_RETURN_CODE(ret) == TDCALL_INVALID_OPERAND)
return -EINVAL;
@@ -105,9 +107,30 @@ int tdx_mcall_get_report0(u8 *reportdata, u8 *tdreport)
}
EXPORT_SYMBOL_GPL(tdx_mcall_get_report0);
+/**
+ * tdx_hcall_get_quote() - Wrapper to request TD Quote using GetQuote
+ * hypercall.
+ * @buf: Address of the directly mapped shared kernel buffer which
+ * contains TDREPORT. The same buffer will be used by VMM to
+ * store the generated TD Quote output.
+ * @size: size of the tdquote buffer (4KB-aligned).
+ *
+ * Refer to section titled "TDG.VP.VMCALL<GetQuote>" in the TDX GHCI
+ * v1.0 specification for more information on GetQuote hypercall.
+ * It is used in the TDX guest driver module to get the TD Quote.
+ *
+ * Return 0 on success or error code on failure.
+ */
+u64 tdx_hcall_get_quote(u8 *buf, size_t size)
+{
+ /* Since buf is a shared memory, set the shared (decrypted) bits */
+ return _tdx_hypercall(TDVMCALL_GET_QUOTE, cc_mkdec(virt_to_phys(buf)), size, 0, 0);
+}
+EXPORT_SYMBOL_GPL(tdx_hcall_get_quote);
+
static void __noreturn tdx_panic(const char *msg)
{
- struct tdx_hypercall_args args = {
+ struct tdx_module_args args = {
.r10 = TDX_HYPERCALL_STANDARD,
.r11 = TDVMCALL_REPORT_FATAL_ERROR,
.r12 = 0, /* Error code: 0 is Panic */
@@ -120,7 +143,7 @@ static void __noreturn tdx_panic(const char *msg)
} message;
/* VMM assumes '\0' in byte 65, if the message took all 64 bytes */
- strncpy(message.str, msg, 64);
+ strtomem_pad(message.str, msg, '\0');
args.r8 = message.r8;
args.r9 = message.r9;
@@ -142,7 +165,7 @@ static void __noreturn tdx_panic(const char *msg)
static void tdx_parse_tdinfo(u64 *cc_mask)
{
- struct tdx_module_output out;
+ struct tdx_module_args args = {};
unsigned int gpa_width;
u64 td_attr;
@@ -153,7 +176,7 @@ static void tdx_parse_tdinfo(u64 *cc_mask)
* Guest-Host-Communication Interface (GHCI), section 2.4.2 TDCALL
* [TDG.VP.INFO].
*/
- tdx_module_call(TDX_GET_INFO, 0, 0, 0, 0, &out);
+ tdcall(TDG_VP_INFO, &args);
/*
* The highest bit of a guest physical address is the "sharing" bit.
@@ -162,7 +185,7 @@ static void tdx_parse_tdinfo(u64 *cc_mask)
* The GPA width that comes out of this call is critical. TDX guests
* can not meaningfully run without it.
*/
- gpa_width = out.rcx & GENMASK(5, 0);
+ gpa_width = args.rcx & GENMASK(5, 0);
*cc_mask = BIT_ULL(gpa_width - 1);
/*
@@ -170,7 +193,7 @@ static void tdx_parse_tdinfo(u64 *cc_mask)
* memory. Ensure that no #VE will be delivered for accesses to
* TD-private memory. Only VMM-shared memory (MMIO) will #VE.
*/
- td_attr = out.rdx;
+ td_attr = args.rdx;
if (!(td_attr & ATTR_SEPT_VE_DISABLE)) {
const char *msg = "TD misconfiguration: SEPT_VE_DISABLE attribute must be set.";
@@ -229,7 +252,7 @@ static int ve_instr_len(struct ve_info *ve)
static u64 __cpuidle __halt(const bool irq_disabled)
{
- struct tdx_hypercall_args args = {
+ struct tdx_module_args args = {
.r10 = TDX_HYPERCALL_STANDARD,
.r11 = hcall_func(EXIT_REASON_HLT),
.r12 = irq_disabled,
@@ -273,7 +296,7 @@ void __cpuidle tdx_safe_halt(void)
static int read_msr(struct pt_regs *regs, struct ve_info *ve)
{
- struct tdx_hypercall_args args = {
+ struct tdx_module_args args = {
.r10 = TDX_HYPERCALL_STANDARD,
.r11 = hcall_func(EXIT_REASON_MSR_READ),
.r12 = regs->cx,
@@ -284,7 +307,7 @@ static int read_msr(struct pt_regs *regs, struct ve_info *ve)
* can be found in TDX Guest-Host-Communication Interface
* (GHCI), section titled "TDG.VP.VMCALL<Instruction.RDMSR>".
*/
- if (__tdx_hypercall_ret(&args))
+ if (__tdx_hypercall(&args))
return -EIO;
regs->ax = lower_32_bits(args.r11);
@@ -294,7 +317,7 @@ static int read_msr(struct pt_regs *regs, struct ve_info *ve)
static int write_msr(struct pt_regs *regs, struct ve_info *ve)
{
- struct tdx_hypercall_args args = {
+ struct tdx_module_args args = {
.r10 = TDX_HYPERCALL_STANDARD,
.r11 = hcall_func(EXIT_REASON_MSR_WRITE),
.r12 = regs->cx,
@@ -314,7 +337,7 @@ static int write_msr(struct pt_regs *regs, struct ve_info *ve)
static int handle_cpuid(struct pt_regs *regs, struct ve_info *ve)
{
- struct tdx_hypercall_args args = {
+ struct tdx_module_args args = {
.r10 = TDX_HYPERCALL_STANDARD,
.r11 = hcall_func(EXIT_REASON_CPUID),
.r12 = regs->ax,
@@ -338,7 +361,7 @@ static int handle_cpuid(struct pt_regs *regs, struct ve_info *ve)
* ABI can be found in TDX Guest-Host-Communication Interface
* (GHCI), section titled "VP.VMCALL<Instruction.CPUID>".
*/
- if (__tdx_hypercall_ret(&args))
+ if (__tdx_hypercall(&args))
return -EIO;
/*
@@ -356,7 +379,7 @@ static int handle_cpuid(struct pt_regs *regs, struct ve_info *ve)
static bool mmio_read(int size, unsigned long addr, unsigned long *val)
{
- struct tdx_hypercall_args args = {
+ struct tdx_module_args args = {
.r10 = TDX_HYPERCALL_STANDARD,
.r11 = hcall_func(EXIT_REASON_EPT_VIOLATION),
.r12 = size,
@@ -365,8 +388,9 @@ static bool mmio_read(int size, unsigned long addr, unsigned long *val)
.r15 = *val,
};
- if (__tdx_hypercall_ret(&args))
+ if (__tdx_hypercall(&args))
return false;
+
*val = args.r11;
return true;
}
@@ -484,7 +508,7 @@ static int handle_mmio(struct pt_regs *regs, struct ve_info *ve)
static bool handle_in(struct pt_regs *regs, int size, int port)
{
- struct tdx_hypercall_args args = {
+ struct tdx_module_args args = {
.r10 = TDX_HYPERCALL_STANDARD,
.r11 = hcall_func(EXIT_REASON_IO_INSTRUCTION),
.r12 = size,
@@ -499,7 +523,7 @@ static bool handle_in(struct pt_regs *regs, int size, int port)
* in TDX Guest-Host-Communication Interface (GHCI) section titled
* "TDG.VP.VMCALL<Instruction.IO>".
*/
- success = !__tdx_hypercall_ret(&args);
+ success = !__tdx_hypercall(&args);
/* Update part of the register affected by the emulated instruction */
regs->ax &= ~mask;
@@ -578,7 +602,7 @@ __init bool tdx_early_handle_ve(struct pt_regs *regs)
void tdx_get_ve_info(struct ve_info *ve)
{
- struct tdx_module_output out;
+ struct tdx_module_args args = {};
/*
* Called during #VE handling to retrieve the #VE info from the
@@ -595,15 +619,15 @@ void tdx_get_ve_info(struct ve_info *ve)
* Note, the TDX module treats virtual NMIs as inhibited if the #VE
* valid flag is set. It means that NMI=>#VE will not result in a #DF.
*/
- tdx_module_call(TDX_GET_VEINFO, 0, 0, 0, 0, &out);
+ tdcall(TDG_VP_VEINFO_GET, &args);
/* Transfer the output parameters */
- ve->exit_reason = out.rcx;
- ve->exit_qual = out.rdx;
- ve->gla = out.r8;
- ve->gpa = out.r9;
- ve->instr_len = lower_32_bits(out.r10);
- ve->instr_info = upper_32_bits(out.r10);
+ ve->exit_reason = args.rcx;
+ ve->exit_qual = args.rdx;
+ ve->gla = args.r8;
+ ve->gpa = args.r9;
+ ve->instr_len = lower_32_bits(args.r10);
+ ve->instr_info = upper_32_bits(args.r10);
}
/*
@@ -704,14 +728,15 @@ static bool tdx_cache_flush_required(void)
}
/*
- * Inform the VMM of the guest's intent for this physical page: shared with
- * the VMM or private to the guest. The VMM is expected to change its mapping
- * of the page in response.
+ * Notify the VMM about page mapping conversion. More info about ABI
+ * can be found in TDX Guest-Host-Communication Interface (GHCI),
+ * section "TDG.VP.VMCALL<MapGPA>".
*/
-static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc)
+static bool tdx_map_gpa(phys_addr_t start, phys_addr_t end, bool enc)
{
- phys_addr_t start = __pa(vaddr);
- phys_addr_t end = __pa(vaddr + numpages * PAGE_SIZE);
+ /* Retrying the hypercall a second time should succeed; use 3 just in case */
+ const int max_retries_per_page = 3;
+ int retry_count = 0;
if (!enc) {
/* Set the shared (decrypted) bits: */
@@ -719,12 +744,51 @@ static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc)
end |= cc_mkdec(0);
}
- /*
- * Notify the VMM about page mapping conversion. More info about ABI
- * can be found in TDX Guest-Host-Communication Interface (GHCI),
- * section "TDG.VP.VMCALL<MapGPA>"
- */
- if (_tdx_hypercall(TDVMCALL_MAP_GPA, start, end - start, 0, 0))
+ while (retry_count < max_retries_per_page) {
+ struct tdx_module_args args = {
+ .r10 = TDX_HYPERCALL_STANDARD,
+ .r11 = TDVMCALL_MAP_GPA,
+ .r12 = start,
+ .r13 = end - start };
+
+ u64 map_fail_paddr;
+ u64 ret = __tdx_hypercall(&args);
+
+ if (ret != TDVMCALL_STATUS_RETRY)
+ return !ret;
+ /*
+ * The guest must retry the operation for the pages in the
+ * region starting at the GPA specified in R11. R11 comes
+ * from the untrusted VMM. Sanity check it.
+ */
+ map_fail_paddr = args.r11;
+ if (map_fail_paddr < start || map_fail_paddr >= end)
+ return false;
+
+ /* "Consume" a retry without forward progress */
+ if (map_fail_paddr == start) {
+ retry_count++;
+ continue;
+ }
+
+ start = map_fail_paddr;
+ retry_count = 0;
+ }
+
+ return false;
+}
+
+/*
+ * Inform the VMM of the guest's intent for this physical page: shared with
+ * the VMM or private to the guest. The VMM is expected to change its mapping
+ * of the page in response.
+ */
+static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc)
+{
+ phys_addr_t start = __pa(vaddr);
+ phys_addr_t end = __pa(vaddr + numpages * PAGE_SIZE);
+
+ if (!tdx_map_gpa(start, end, enc))
return false;
/* shared->private conversion requires memory to be accepted before use */
@@ -760,6 +824,10 @@ static bool tdx_enc_status_change_finish(unsigned long vaddr, int numpages,
void __init tdx_early_init(void)
{
+ struct tdx_module_args args = {
+ .rdx = TDCS_NOTIFY_ENABLES,
+ .r9 = -1ULL,
+ };
u64 cc_mask;
u32 eax, sig[3];
@@ -770,12 +838,15 @@ void __init tdx_early_init(void)
setup_force_cpu_cap(X86_FEATURE_TDX_GUEST);
+ /* TSC is the only reliable clock in TDX guest */
+ setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
+
cc_vendor = CC_VENDOR_INTEL;
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);
+ tdcall(TDG_VM_WR, &args);
/*
* All bits above GPA width are reserved and kernel treats shared bit