[RFC PATCH v3 20/59] KVM: Add per-VM flag to disable dirty logging of memslots for TDs

isaku.yamahata
2021-11-25T00:25:02Z

From: Sean Christopherson <sean.j.christopherson@intel.com>

Add a flag for TDX to mark dirty logging as unsupported.

Suggested-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
include/linux/kvm_host.h | 1 +
virt/kvm/kvm_main.c | 5 ++++-
2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index d59debe99212..08284807d48e 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -624,6 +624,7 @@ struct kvm {
struct notifier_block pm_notifier;
#endif
char stats_id[KVM_STATS_NAME_SIZE];
+ bool dirty_log_unsupported;
#ifdef __KVM_HAVE_READONLY_MEM
bool readonly_mem_unsupported;
#endif
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index aaa6d69265ea..5bf456734e7d 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1425,7 +1425,10 @@ static void update_memslots(struct kvm_memslots *slots,
static int check_memory_region_flags(struct kvm *kvm,
const struct kvm_userspace_memory_region *mem)
{
- u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES;
+ u32 valid_flags = 0;
+
+ if (!kvm->dirty_log_unsupported)
+ valid_flags |= KVM_MEM_LOG_DIRTY_PAGES;

#ifdef __KVM_HAVE_READONLY_MEM
if (!kvm->readonly_mem_unsupported)
--
2.25.1