[PATCH v3 54/70] i386/tdx: handle TDG.VP.VMCALL hypercall

Xiaoyao Li
2023-11-15T07:22:41Z

From: Isaku Yamahata <isaku.yamahata@intel.com>

MapGPA is a hypercall to convert GPA from/to private GPA to/from shared GPA.
As the conversion function is already implemented as kvm_convert_memory,
wire it to TDX hypercall exit.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
---
accel/kvm/kvm-all.c | 2 +-
include/sysemu/kvm.h | 2 ++
target/i386/kvm/tdx.c | 37 +++++++++++++++++++++++++++++++++++++
3 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 89e7183a2738..65bc92265369 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -2929,7 +2929,7 @@ static void kvm_eat_signals(CPUState *cpu)
} while (sigismember(&chkset, SIG_IPI));
}

-static int kvm_convert_memory(hwaddr start, hwaddr size, bool to_private)
+int kvm_convert_memory(hwaddr start, hwaddr size, bool to_private)
{
MemoryRegionSection section;
ram_addr_t offset;
diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index 2f6592859ac6..e0061848b053 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -544,4 +544,6 @@ int kvm_create_guest_memfd(uint64_t size, uint64_t flags, Error **errp);

int kvm_set_memory_attributes_private(hwaddr start, hwaddr size);
int kvm_set_memory_attributes_shared(hwaddr start, hwaddr size);
+
+int kvm_convert_memory(hwaddr start, hwaddr size, bool to_private);
#endif
diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index 3b87c36c485e..b17258f17fd0 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -1001,6 +1001,7 @@ static void tdx_guest_class_init(ObjectClass *oc, void *data)
{
}

+#define TDG_VP_VMCALL_MAP_GPA 0x10001ULL
#define TDG_VP_VMCALL_GET_QUOTE 0x10002ULL
#define TDG_VP_VMCALL_SETUP_EVENT_NOTIFY_INTERRUPT 0x10004ULL

@@ -1060,6 +1061,39 @@ static hwaddr tdx_shared_bit(X86CPU *cpu)
return (cpu->phys_bits > 48) ? BIT_ULL(51) : BIT_ULL(47);
}

+static void tdx_handle_map_gpa(X86CPU *cpu, struct kvm_tdx_vmcall *vmcall)
+{
+ hwaddr shared_bit = tdx_shared_bit(cpu);
+ hwaddr gpa = vmcall->in_r12 & ~shared_bit;
+ bool private = !(vmcall->in_r12 & shared_bit);
+ hwaddr size = vmcall->in_r13;
+ int ret = 0;
+
+ vmcall->status_code = TDG_VP_VMCALL_INVALID_OPERAND;
+
+ if (!QEMU_IS_ALIGNED(gpa, 4096) || !QEMU_IS_ALIGNED(size, 4096)) {
+ vmcall->status_code = TDG_VP_VMCALL_ALIGN_ERROR;
+ return;
+ }
+
+ /* Overflow case. */
+ if (gpa + size < gpa) {
+ return;
+ }
+ if (gpa >= (1ULL << cpu->phys_bits) ||
+ gpa + size >= (1ULL << cpu->phys_bits)) {
+ return;
+ }
+
+ if (size > 0) {
+ ret = kvm_convert_memory(gpa, size, private);
+ }
+
+ if (!ret) {
+ vmcall->status_code = TDG_VP_VMCALL_SUCCESS;
+ }
+}
+
struct tdx_get_quote_task {
uint32_t apic_id;
hwaddr gpa;
@@ -1455,6 +1489,9 @@ static void tdx_handle_vmcall(X86CPU *cpu, struct kvm_tdx_vmcall *vmcall)
}

switch (vmcall->subfunction) {
+ case TDG_VP_VMCALL_MAP_GPA:
+ tdx_handle_map_gpa(cpu, vmcall);
+ break;
case TDG_VP_VMCALL_GET_QUOTE:
tdx_handle_get_quote(cpu, vmcall);
break;
--
2.34.1