KVM: SVM: Consider NUMA affinity when allocating per-CPU save_area

KVM: SVM: Consider NUMA affinity when allocating per-CPU save_area

save_area of per-CPU svm_data are dominantly accessed from their
own local CPUs, so allocate them node-local for performance reason

so rename __snp_safe_alloc_page as snp_safe_alloc_page_node which
accepts numa node id as input parameter, svm_cpu_init call it with
node id switched from cpu id

Signed-off-by: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20240520120858.13117-4-lirongqing@baidu.com
Signed-off-by: Sean Christopherson <seanjc@google.com>