[v10,3/3] KVM: arm64: Dirty quota-based throttling of vcpus

Commit Message

Shivam Kumar Feb. 21, 2024, 7:51 p.m. UTC

Call update_dirty_quota whenever a page is marked dirty with
appropriate arch-specific page size. Process the KVM request
KVM_REQ_DIRTY_QUOTA_EXIT (raised by update_dirty_quota) to exit to
userspace with exit reason KVM_EXIT_DIRTY_QUOTA_EXHAUSTED.

Suggested-by: Shaju Abraham <[e-mail]>
Suggested-by: Manish Mishra <[e-mail]>
Co-developed-by: Anurag Madnawat <[e-mail]>
Signed-off-by: Anurag Madnawat <[e-mail]>
Signed-off-by: Shivam Kumar <[e-mail]>
---
 arch/arm64/kvm/Kconfig | 1 +
 arch/arm64/kvm/arm.c   | 5 +++++
 arch/arm64/kvm/mmu.c   | 1 +
 3 files changed, 7 insertions(+)

Patch

diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 27ca89b628a0..f66d872d0830 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -39,6 +39,7 @@  menuconfig KVM
 	select SCHED_INFO
 	select GUEST_PERF_EVENTS if PERF_EVENTS
 	select XARRAY_MULTI
+	select HAVE_KVM_DIRTY_QUOTA
 	help
 	  Support hosting virtualized guest machines.
 
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index a25265aca432..dde02c372551 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -872,6 +872,11 @@  static int check_vcpu_requests(struct kvm_vcpu *vcpu)
 
 		if (kvm_dirty_ring_check_request(vcpu))
 			return 0;
+
+		if (kvm_check_request(KVM_REQ_DIRTY_QUOTA_EXIT, vcpu)) {
+			vcpu->run->exit_reason = KVM_EXIT_DIRTY_QUOTA_EXHAUSTED;
+			return 0;
+		}
 	}
 
 	return 1;
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index d14504821b79..77088bf9a502 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1579,6 +1579,7 @@  static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 	/* Mark the page dirty only if the fault is handled successfully */
 	if (writable && !ret) {
 		kvm_set_pfn_dirty(pfn);
+		update_dirty_quota(kvm, vma_pagesize);
 		mark_page_dirty_in_slot(kvm, memslot, gfn);
 	}