On 7/23/2025 6:46 PM, Fuad Tabba wrote:
The original name was vague regarding its functionality. This Kconfig
option specifically enables and gates the kvm_gmem_populate() function,
which is responsible for populating a GPA range with guest data.
The new name, HAVE_KVM_ARCH_GMEM_POPULATE, describes the purpose of the
option: to enable arch-specific guest_memfd population mechanisms. It
also follows the same pattern as the other HAVE_KVM_ARCH_* configuration
options.
This improves clarity for developers and ensures the name accurately
reflects the functionality it controls, especially as guest_memfd
support expands beyond purely "private" memory scenarios.
Note that the vm type KVM_X86_SW_PROTECTED_VM does not need the populate
function. Therefore, ensure that the correct configuration is selected
when KVM_SW_PROTECTED_VM is enabled.
the changelog needs to be enhanced. At least it doesn't talk about
KVM_X86_PRIVATE_MEM at all.
If Sean is going to queue this version, I think he can help refine it
when queuing.
Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>
Reviewed-by: Shivank Garg <shivankg@xxxxxxx>
Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>
Co-developed-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Co-developed-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Fuad Tabba <tabba@xxxxxxxxxx>
Reviewed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
---
arch/x86/kvm/Kconfig | 14 ++++++++++----
include/linux/kvm_host.h | 2 +-
virt/kvm/Kconfig | 9 ++++-----
virt/kvm/guest_memfd.c | 2 +-
4 files changed, 16 insertions(+), 11 deletions(-)
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index 13ab7265b505..c763446d9b9f 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -79,11 +79,16 @@ config KVM_WERROR
If in doubt, say "N".
+config KVM_X86_PRIVATE_MEM
+ select KVM_GENERIC_MEMORY_ATTRIBUTES
+ select KVM_GUEST_MEMFD
+ bool
+
config KVM_SW_PROTECTED_VM
bool "Enable support for KVM software-protected VMs"
depends on EXPERT
depends on KVM_X86 && X86_64
- select KVM_GENERIC_PRIVATE_MEM
+ select KVM_X86_PRIVATE_MEM
help
Enable support for KVM software-protected VMs. Currently, software-
protected VMs are purely a development and testing vehicle for
@@ -133,8 +138,8 @@ config KVM_INTEL_TDX
bool "Intel Trust Domain Extensions (TDX) support"
default y
depends on INTEL_TDX_HOST
- select KVM_GENERIC_PRIVATE_MEM
- select KVM_GENERIC_MEMORY_ATTRIBUTES
+ select KVM_X86_PRIVATE_MEM
+ select HAVE_KVM_ARCH_GMEM_POPULATE
help
Provides support for launching Intel Trust Domain Extensions (TDX)
confidential VMs on Intel processors.
@@ -157,9 +162,10 @@ config KVM_AMD_SEV
depends on KVM_AMD && X86_64
depends on CRYPTO_DEV_SP_PSP && !(KVM_AMD=y && CRYPTO_DEV_CCP_DD=m)
select ARCH_HAS_CC_PLATFORM
- select KVM_GENERIC_PRIVATE_MEM
+ select KVM_X86_PRIVATE_MEM
select HAVE_KVM_ARCH_GMEM_PREPARE
select HAVE_KVM_ARCH_GMEM_INVALIDATE
+ select HAVE_KVM_ARCH_GMEM_POPULATE
help
Provides support for launching encrypted VMs which use Secure
Encrypted Virtualization (SEV), Secure Encrypted Virtualization with
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 8cdc0b3cc1b1..ddfb6cfe20a6 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -2534,7 +2534,7 @@ static inline int kvm_gmem_get_pfn(struct kvm *kvm,
int kvm_arch_gmem_prepare(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, int max_order);
#endif
-#ifdef CONFIG_KVM_GENERIC_PRIVATE_MEM
+#ifdef CONFIG_HAVE_KVM_ARCH_GMEM_POPULATE
/**
* kvm_gmem_populate() - Populate/prepare a GPA range with guest data
*
diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
index e4b400feff94..1b7d5be0b6c4 100644
--- a/virt/kvm/Kconfig
+++ b/virt/kvm/Kconfig
@@ -116,11 +116,6 @@ config KVM_GUEST_MEMFD
select XARRAY_MULTI
bool
-config KVM_GENERIC_PRIVATE_MEM
- select KVM_GENERIC_MEMORY_ATTRIBUTES
- select KVM_GUEST_MEMFD
- bool
-
config HAVE_KVM_ARCH_GMEM_PREPARE
bool
depends on KVM_GUEST_MEMFD
@@ -128,3 +123,7 @@ config HAVE_KVM_ARCH_GMEM_PREPARE
config HAVE_KVM_ARCH_GMEM_INVALIDATE
bool
depends on KVM_GUEST_MEMFD
+
+config HAVE_KVM_ARCH_GMEM_POPULATE
+ bool
+ depends on KVM_GUEST_MEMFD
diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
index 7d85cc33c0bb..b2b50560e80e 100644
--- a/virt/kvm/guest_memfd.c
+++ b/virt/kvm/guest_memfd.c
@@ -627,7 +627,7 @@ int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot,
}
EXPORT_SYMBOL_GPL(kvm_gmem_get_pfn);
-#ifdef CONFIG_KVM_GENERIC_PRIVATE_MEM
+#ifdef CONFIG_HAVE_KVM_ARCH_GMEM_POPULATE
long kvm_gmem_populate(struct kvm *kvm, gfn_t start_gfn, void __user *src, long npages,
kvm_gmem_populate_cb post_populate, void *opaque)
{
