On 12/11/2011 12:24 PM, Christoffer Dall wrote:

This commit introduces the framework for guest memory management
through the use of 2nd stage translation. Each VM has a pointer
to a level-1 tabled (the pgd field in struct kvm_arch) which is
used for the 2nd stage translations. Entries are added when handling
guest faults (later patch) and the table itself can be allocated and
freed through the following functions implemented in
arch/arm/kvm/arm_mmu.c:
 - kvm_alloc_stage2_pgd(struct kvm *kvm);
 - kvm_free_stage2_pgd(struct kvm *kvm);

Further, each entry in TLBs and caches are tagged with a VMID
identifier in addition to ASIDs. The VMIDs are managed using
a bitmap and assigned when creating the VM in kvm_arch_init_vm()
where the 2nd stage pgd is also allocated. The table is freed in
kvm_arch_destroy_vm(). Both functions are called from the main
KVM code.

 
 struct kvm_arch {
-	pgd_t *pgd;     /* 1-level 2nd stage table */
+	u32    vmid;	/* The VMID used for the virt. memory system */
+	pgd_t *pgd;	/* 1-level 2nd stage table */
+	u64    vttbr;	/* VTTBR value associated with above pgd and vmid */
 };

I can't say I have a solid grasp here, but my feeling is that vmid needs
to be per-vcpu.  Otherwise vcpu 1 can migrate to a cpu that previously
ran vcpu 0, and reuse its tlb since they have the same vmid.

-- 
error compiling committee.c: too many arguments to function