在 2023年02月21日 01:46, Paolo Bonzini 写道:
On 2/20/23 07:57, Tianrui Zhao wrote:
+ order = get_order(kvm_vector_size + kvm_enter_guest_size);
+ addr = (void *)__get_free_pages(GFP_KERNEL, order);
+ if (!addr) {
+ free_percpu(vmcs);
+ return -ENOMEM;
+ }
+
+ memcpy(addr, kvm_vector_entry, kvm_vector_size);
+ memcpy(addr + kvm_vector_size, kvm_enter_guest,
kvm_enter_guest_size);
+ flush_icache_range((unsigned long)addr, (unsigned long)addr +
+ kvm_vector_size + kvm_enter_guest_size);
+
+ vpid_mask = read_csr_gstat();
+ vpid_mask = (vpid_mask & CSR_GSTAT_GIDBIT) >>
CSR_GSTAT_GIDBIT_SHIFT;
+ if (vpid_mask)
+ vpid_mask = GENMASK(vpid_mask - 1, 0);
+
+ for_each_possible_cpu(cpu) {
+ context = per_cpu_ptr(vmcs, cpu);
+ context->vpid_mask = vpid_mask;
+ context->vpid_cache = context->vpid_mask + 1;
+ context->last_vcpu = NULL;
+ context->kvm_eentry = addr;
+ context->kvm_enter_guest = addr + kvm_vector_size;
+ context->page_order = order;
+ }
A lot of these variables are constant across all pCPUs, any reason to
have them in a per-CPU variable? Likewise, since they are all the
same as the constant global vmcs variable, why make them part of
struct kvm_context instead of just making them globals?
Ok thanks, it is more appropriate to use global variables to save those
information.
Thanks
Tianrui Zhao
Also, why does the world switch code need a copy?
Paolo
