A fully enlightened TDX guest on Hyper-V (i.e. without the paravisor) only
uses the GHCI call rather than hv_hypercall_pg.
In hv_do_hypercall(), Hyper-V requires that the input/output addresses
must have the cc_mask.
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
---
arch/x86/hyperv/hv_init.c | 8 ++++++++
arch/x86/hyperv/ivm.c | 17 +++++++++++++++++
arch/x86/include/asm/mshyperv.h | 15 +++++++++++++++
drivers/hv/hv_common.c | 10 ++++++++--
include/asm-generic/mshyperv.h | 1 +
5 files changed, 49 insertions(+), 2 deletions(-)
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 547ebf6a03bc9..d8ea54663113c 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -481,6 +481,10 @@ void __init hyperv_init(void)
/* Hyper-V requires to write guest os id via ghcb in SNP IVM. */
hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, guest_id);
+ /* A TDX guest uses the GHCI call rather than hv_hypercall_pg. */
+ if (hv_isolation_type_tdx())
+ goto skip_hypercall_pg_init;
+
hv_hypercall_pg = __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START,
VMALLOC_END, GFP_KERNEL, PAGE_KERNEL_ROX,
VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
@@ -520,6 +524,7 @@ void __init hyperv_init(void)
wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
}
+skip_hypercall_pg_init:
/*
* hyperv_init() is called before LAPIC is initialized: see
* apic_intr_mode_init() -> x86_platform.apic_post_init() and
@@ -647,6 +652,9 @@ bool hv_is_hyperv_initialized(void)
if (x86_hyper_type != X86_HYPER_MS_HYPERV)
return false;
+ /* A TDX guest uses the GHCI call rather than hv_hypercall_pg. */
+ if (hv_isolation_type_tdx())
+ return true;
/*
* Verify that earlier initialization succeeded by checking
* that the hypercall page is setup
diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
index d4aafe8b6b50d..5792cddea4914 100644
--- a/arch/x86/hyperv/ivm.c
+++ b/arch/x86/hyperv/ivm.c
@@ -533,3 +533,20 @@ bool hv_isolation_type_tdx(void)
{
return static_branch_unlikely(&isolation_type_tdx);
}
+
+#ifdef CONFIG_INTEL_TDX_GUEST
+
+u64 hv_tdx_hypercall(u64 control, u64 param1, u64 param2)
+{
+ struct tdx_hypercall_args args = { };
+
+ args.r10 = control;
+ args.rdx = param1;
+ args.r8 = param2;
+
+ (void)__tdx_hypercall_ret(&args);
+
+ return args.r11;
+}
+
+#endif
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 83fc3a79f1557..4c68564a165e5 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -61,7 +61,12 @@ int hv_call_add_logical_proc(int node, u32 lp_index, u32 acpi_id);
int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags);
bool hv_isolation_type_tdx(void);
+u64 hv_tdx_hypercall(u64 control, u64 param1, u64 param2);
+/*
+ * If the hypercall involves no input or output parameters, the hypervisor
+ * ignores the corresponding GPA pointer.
+ */
static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
{
u64 input_address = input ? virt_to_phys(input) : 0;
@@ -69,6 +74,10 @@ static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
u64 hv_status;
#ifdef CONFIG_X86_64
+ if (hv_isolation_type_tdx())
+ return hv_tdx_hypercall(control,
+ cc_mkdec(input_address),
+ cc_mkdec(output_address));
if (!hv_hypercall_pg)
return U64_MAX;
@@ -112,6 +121,9 @@ static inline u64 _hv_do_fast_hypercall8(u64 control, u64 input1)
u64 hv_status;
#ifdef CONFIG_X86_64
+ if (hv_isolation_type_tdx())
+ return hv_tdx_hypercall(control, input1, 0);
+
{
__asm__ __volatile__("mov %[thunk_target], %%r8\n"
ALTERNATIVE(CALL_NOSPEC, "vmmcall", X86_FEATURE_SEV_ES)
@@ -158,6 +170,9 @@ static inline u64 _hv_do_fast_hypercall16(u64 control, u64 input1, u64 input2)
u64 hv_status;
#ifdef CONFIG_X86_64
+ if (hv_isolation_type_tdx())
+ return hv_tdx_hypercall(control, input1, input2);
+
{
__asm__ __volatile__("mov %[output], %%r8\n"
ALTERNATIVE(CALL_NOSPEC, "vmmcall", X86_FEATURE_SEV_ES)
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index da3307533f4d7..897bbb96f4118 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -381,10 +381,10 @@ int hv_common_cpu_init(unsigned int cpu)
*outputarg = (char *)(*inputarg) + HV_HYP_PAGE_SIZE;
}
- if (hv_isolation_type_en_snp()) {
+ if (hv_isolation_type_en_snp() || hv_isolation_type_tdx()) {
ret = set_memory_decrypted((unsigned long)*inputarg, pgcount);
if (ret) {
- kfree(*inputarg);
+ /* It may be unsafe to free *inputarg */
*inputarg = NULL;
return ret;
}
@@ -567,3 +567,9 @@ u64 __weak hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_s
return HV_STATUS_INVALID_PARAMETER;
}
EXPORT_SYMBOL_GPL(hv_ghcb_hypercall);
+
+u64 __weak hv_tdx_hypercall(u64 control, u64 param1, u64 param2)
+{
+ return HV_STATUS_INVALID_PARAMETER;
+}
+EXPORT_SYMBOL_GPL(hv_tdx_hypercall);
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index c5e657c3cdf4c..30fa75facd784 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -283,6 +283,7 @@ enum hv_isolation_type hv_get_isolation_type(void);
bool hv_is_isolation_supported(void);
bool hv_isolation_type_snp(void);
u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size);
+u64 hv_tdx_hypercall(u64 control, u64 param1, u64 param2);
void hyperv_cleanup(void);
bool hv_query_ext_cap(u64 cap_query);
void hv_setup_dma_ops(struct device *dev, bool coherent);
--
2.25.1
