diff options
| -rw-r--r-- | executor/common_kvm_amd64_syzos.h | 18 | ||||
| -rw-r--r-- | sys/linux/dev_kvm_amd64.txt | 6 | ||||
| -rw-r--r-- | sys/linux/test/amd64-syz_kvm_nested_amd_invlpga | 35 |
3 files changed, 59 insertions, 0 deletions
diff --git a/executor/common_kvm_amd64_syzos.h b/executor/common_kvm_amd64_syzos.h index df1f63ad5..58444fbc1 100644 --- a/executor/common_kvm_amd64_syzos.h +++ b/executor/common_kvm_amd64_syzos.h @@ -33,6 +33,7 @@ typedef enum { SYZOS_API_NESTED_VMRESUME = 304, SYZOS_API_NESTED_INTEL_VMWRITE_MASK = 340, SYZOS_API_NESTED_AMD_VMCB_WRITE_MASK = 380, + SYZOS_API_NESTED_AMD_INVLPGA = 381, SYZOS_API_STOP, // Must be the last one } syzos_api_id; @@ -113,6 +114,7 @@ GUEST_CODE static void guest_handle_nested_vmlaunch(struct api_call_1* cmd, uint GUEST_CODE static void guest_handle_nested_vmresume(struct api_call_1* cmd, uint64 cpu_id); GUEST_CODE static void guest_handle_nested_intel_vmwrite_mask(struct api_call_5* cmd, uint64 cpu_id); GUEST_CODE static void guest_handle_nested_amd_vmcb_write_mask(struct api_call_5* cmd, uint64 cpu_id); +GUEST_CODE static void guest_handle_nested_amd_invlpga(struct api_call_2* cmd, uint64 cpu_id); typedef enum { UEXIT_END = (uint64)-1, @@ -228,6 +230,9 @@ guest_main(uint64 size, uint64 cpu) } else if (call == SYZOS_API_NESTED_AMD_VMCB_WRITE_MASK) { // Write to a VMCB field using masks. guest_handle_nested_amd_vmcb_write_mask((struct api_call_5*)cmd, cpu); + } else if (call == SYZOS_API_NESTED_AMD_INVLPGA) { + // Invalidate TLB mappings for the specified address/ASID. + guest_handle_nested_amd_invlpga((struct api_call_2*)cmd, cpu); } addr += cmd->size; size -= cmd->size; @@ -1282,4 +1287,17 @@ guest_handle_nested_amd_vmcb_write_mask(struct api_call_5* cmd, uint64 cpu_id) vmcb_write64(vmcb_addr, offset, new_value); } +GUEST_CODE static noinline void +guest_handle_nested_amd_invlpga(struct api_call_2* cmd, uint64 cpu_id) +{ + if (get_cpu_vendor() != CPU_VENDOR_AMD) + return; + + uint64 linear_addr = cmd->args[0]; + // ASID (Address Space ID) - only lower 16 bits matter usually, but register is 32-bit. + uint32 asid = (uint32)cmd->args[1]; + + asm volatile("invlpga" : : "a"(linear_addr), "c"(asid) : "memory"); +} + #endif // EXECUTOR_COMMON_KVM_AMD64_SYZOS_H diff --git a/sys/linux/dev_kvm_amd64.txt b/sys/linux/dev_kvm_amd64.txt index c68528e34..abdde5644 100644 --- a/sys/linux/dev_kvm_amd64.txt +++ b/sys/linux/dev_kvm_amd64.txt @@ -147,6 +147,11 @@ syzos_api_nested_amd_vmcb_write_mask { flip_mask int64 } +syzos_api_nested_amd_invlpga { + addr flags[kvm_guest_addrs, int64] + asid int64[0:65535] +} + # IDs here must match those in executor/common_kvm_amd64_syzos.h. syzos_api_call$x86 [ uexit syzos_api$x86[0, intptr] @@ -166,6 +171,7 @@ syzos_api_call$x86 [ nested_vmresume syzos_api$x86[304, syzos_api_vm_id] nested_intel_vmwrite_mask syzos_api$x86[340, syzos_api_nested_intel_vmwrite_mask] nested_amd_vmcb_write_mask syzos_api$x86[380, syzos_api_nested_amd_vmcb_write_mask] + nested_amd_invlpga syzos_api$x86[381, syzos_api_nested_amd_invlpga] ] [varlen] kvm_text_x86 [ diff --git a/sys/linux/test/amd64-syz_kvm_nested_amd_invlpga b/sys/linux/test/amd64-syz_kvm_nested_amd_invlpga new file mode 100644 index 000000000..e7a8b1f67 --- /dev/null +++ b/sys/linux/test/amd64-syz_kvm_nested_amd_invlpga @@ -0,0 +1,35 @@ +# +# requires: arch=amd64 -threaded +# +r0 = openat$kvm(0, &AUTO='/dev/kvm\x00', 0x0, 0x0) +r1 = ioctl$KVM_CREATE_VM(r0, AUTO, 0x0) +r2 = syz_kvm_setup_syzos_vm$x86(r1, &(0x7f0000c00000/0x400000)=nil) + +# Test L0 emulation of the AMD SVM INVLPGA instruction. +# +# 1. Setup nested environment (L1). +# 2. L1 executes INVLPGA with specific ASID and Linear Address. +# - This triggers a VMEXIT to L0. +# - L0 must emulate the invalidation in its Shadow MMU / NPT. +# - L0 resumes L1. +# 3. L1 executes UEXIT(0xface) to signal survival. +# +# Arguments for INVLPGA: +# Arg 0: Linear Address (e.g., 0x400000) +# Arg 1: ASID (e.g., 1) +# +r3 = syz_kvm_add_vcpu$x86(r2, &AUTO={0x0, &AUTO=[@enable_nested={AUTO, AUTO, 0x0}, @nested_create_vm={AUTO, AUTO, 0x0}, @nested_amd_invlpga={AUTO, AUTO, {0x400000, 0x1}}, @uexit={AUTO, AUTO, 0xface}], AUTO}) +r4 = ioctl$KVM_GET_VCPU_MMAP_SIZE(r0, AUTO) +r5 = mmap$KVM_VCPU(&(0x7f0000009000/0x1000)=nil, r4, 0x3, 0x1, r3, 0x0) + +# Run the VCPU. +# We expect the guest to execute INVLPGA (handled transparently by L0) +# and then immediately yield with UEXIT code 0xface. +# +ioctl$KVM_RUN(r3, AUTO, 0x0) +syz_kvm_assert_syzos_uexit$x86(r5, 0xface) + +# guest_main should finish with guest_uexit(-1). +# +ioctl$KVM_RUN(r3, AUTO, 0x0) +syz_kvm_assert_syzos_uexit$x86(r5, 0xffffffff) |