| Message ID | 20250318161823.4005529-6-tabba@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | KVM: Mapping guest_memfd backed memory at the host for software protected VMs | expand |
Hi Fuad, kernel test robot noticed the following build errors: [auto build test ERROR on 4701f33a10702d5fc577c32434eb62adde0a1ae1] url: https://github.com/intel-lab-lkp/linux/commits/Fuad-Tabba/mm-Consolidate-freeing-of-typed-folios-on-final-folio_put/20250319-003340 base: 4701f33a10702d5fc577c32434eb62adde0a1ae1 patch link: https://lore.kernel.org/r/20250318161823.4005529-6-tabba%40google.com patch subject: [PATCH v7 5/9] KVM: x86: Mark KVM_X86_SW_PROTECTED_VM as supporting guest_memfd shared memory config: x86_64-randconfig-078-20250326 (https://download.01.org/0day-ci/archive/20250326/202503262202.WSGvs92t-lkp@intel.com/config) compiler: clang version 20.1.1 (https://github.com/llvm/llvm-project 424c2d9b7e4de40d0804dd374721e6411c27d1d1) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250326/202503262202.WSGvs92t-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202503262202.WSGvs92t-lkp@intel.com/ All errors (new ones prefixed by >>): >> ld.lld: error: undefined symbol: kvm_gmem_handle_folio_put >>> referenced by swap.c:110 (mm/swap.c:110) >>> mm/swap.o:(free_typed_folio) in archive vmlinux.a
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 32ae3aa50c7e..b874e54a5ee4 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -2246,8 +2246,13 @@ void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, #ifdef CONFIG_KVM_PRIVATE_MEM #define kvm_arch_has_private_mem(kvm) ((kvm)->arch.has_private_mem) + +#define kvm_arch_gmem_supports_shared_mem(kvm) \ + (IS_ENABLED(CONFIG_KVM_GMEM_SHARED_MEM) && \ + ((kvm)->arch.vm_type == KVM_X86_SW_PROTECTED_VM)) #else #define kvm_arch_has_private_mem(kvm) false +#define kvm_arch_gmem_supports_shared_mem(kvm) false #endif #define kvm_arch_has_readonly_mem(kvm) (!(kvm)->arch.has_protected_state) diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index ea2c4f21c1ca..22d1bcdaad58 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -45,7 +45,8 @@ config KVM_X86 select HAVE_KVM_PM_NOTIFIER if PM select KVM_GENERIC_HARDWARE_ENABLING select KVM_GENERIC_PRE_FAULT_MEMORY - select KVM_GENERIC_PRIVATE_MEM if KVM_SW_PROTECTED_VM + select KVM_PRIVATE_MEM if KVM_SW_PROTECTED_VM + select KVM_GMEM_SHARED_MEM if KVM_SW_PROTECTED_VM select KVM_WERROR if WERROR config KVM
The KVM_X86_SW_PROTECTED_VM type is meant for experimentation and does not have any underlying support for protected guests. This makes it a good candidate for testing mapping shared memory. Therefore, when the kconfig option is enabled, mark KVM_X86_SW_PROTECTED_VM as supporting shared memory. This means that this memory is considered by guest_memfd to be shared with the host, with the possibility of in-place conversion between shared and private. This allows the host to map and fault in guest_memfd memory belonging to this VM type. Signed-off-by: Fuad Tabba <tabba@google.com> --- arch/x86/include/asm/kvm_host.h | 5 +++++ arch/x86/kvm/Kconfig | 3 ++- 2 files changed, 7 insertions(+), 1 deletion(-)