xen: fix logical error in tlb flushing

While TLB_FLUSH_ALL gets passed as 'end' argument to
flush_tlb_others(), the Xen code was made to check its 'start'
parameter. That may give a incorrect op.cmd to MMUEXT_INVLPG_MULTI
instead of MMUEXT_TLB_FLUSH_MULTI. Then it causes some page can not
be flushed from TLB.

This patch fixed this issue.

Reported-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Alex Shi <alex.shi@intel.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Yongjie Ren <yongjie.ren@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index b65a76133f4f9b4f51dc426021975d7a5427191e..5141d808e7519d8f38ca8c001e4e5c6c7b318956 100644 (file)
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1283,7 +1283,7 @@ static void xen_flush_tlb_others(const struct cpumask *cpus,
        cpumask_clear_cpu(smp_processor_id(), to_cpumask(args->mask));
 
        args->op.cmd = MMUEXT_TLB_FLUSH_MULTI;
-       if (start != TLB_FLUSH_ALL && (end - start) <= PAGE_SIZE) {
+       if (end != TLB_FLUSH_ALL && (end - start) <= PAGE_SIZE) {
                args->op.cmd = MMUEXT_INVLPG_MULTI;
                args->op.arg1.linear_addr = start;
        }