[Xen-devel] [PATCH v2 1/3] x86/hypervisor: pass flags to hypervisor_flush_tlb

[Wei Liu <wl@xen.org>]

Hyper-V's L0 assisted flush has fine-grained control over what gets
flushed. We need all the flags available to make the best decisions
possible.

No functional change because Xen's implementation doesn't care about
what is passed to it.

Signed-off-by: Wei Liu <liuwe@microsoft.com>
---
v2:
1. Introduce FLUSH_TLB_FLAGS_MASK
---
 xen/arch/x86/guest/hypervisor.c        |  7 +++++--
 xen/arch/x86/guest/xen/xen.c           |  2 +-
 xen/arch/x86/smp.c                     |  5 ++---
 xen/include/asm-x86/flushtlb.h         |  3 +++
 xen/include/asm-x86/guest/hypervisor.h | 10 +++++-----
 5 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/xen/arch/x86/guest/hypervisor.c b/xen/arch/x86/guest/hypervisor.c
index 47e938e287..6ee28c9df1 100644
--- a/xen/arch/x86/guest/hypervisor.c
+++ b/xen/arch/x86/guest/hypervisor.c
@@ -75,10 +75,13 @@ void __init hypervisor_e820_fixup(struct e820map *e820)
 }
 
 int hypervisor_flush_tlb(const cpumask_t *mask, const void *va,
-                         unsigned int order)
+                         unsigned int flags)
 {
+    if ( flags & ~FLUSH_TLB_FLAGS_MASK )
+        return -EINVAL;
+
     if ( ops.flush_tlb )
-        return alternative_call(ops.flush_tlb, mask, va, order);
+        return alternative_call(ops.flush_tlb, mask, va, flags);
 
     return -ENOSYS;
 }
diff --git a/xen/arch/x86/guest/xen/xen.c b/xen/arch/x86/guest/xen/xen.c
index 5d3427a713..0eb1115c4d 100644
--- a/xen/arch/x86/guest/xen/xen.c
+++ b/xen/arch/x86/guest/xen/xen.c
@@ -324,7 +324,7 @@ static void __init e820_fixup(struct e820map *e820)
         pv_shim_fixup_e820(e820);
 }
 
-static int flush_tlb(const cpumask_t *mask, const void *va, unsigned int order)
+static int flush_tlb(const cpumask_t *mask, const void *va, unsigned int flags)
 {
     return xen_hypercall_hvm_op(HVMOP_flush_tlbs, NULL);
 }
diff --git a/xen/arch/x86/smp.c b/xen/arch/x86/smp.c
index 9bc925616a..2ab0e30eef 100644
--- a/xen/arch/x86/smp.c
+++ b/xen/arch/x86/smp.c
@@ -258,9 +258,8 @@ void flush_area_mask(const cpumask_t *mask, const void *va, unsigned int flags)
          !cpumask_subset(mask, cpumask_of(cpu)) )
     {
         if ( cpu_has_hypervisor &&
-             !(flags & ~(FLUSH_TLB | FLUSH_TLB_GLOBAL | FLUSH_VA_VALID |
-                         FLUSH_ORDER_MASK)) &&
-             !hypervisor_flush_tlb(mask, va, flags & FLUSH_ORDER_MASK) )
+             !(flags & ~FLUSH_TLB_FLAGS_MASK) &&
+             !hypervisor_flush_tlb(mask, va, flags) )
         {
             if ( tlb_clk_enabled )
                 tlb_clk_enabled = false;
diff --git a/xen/include/asm-x86/flushtlb.h b/xen/include/asm-x86/flushtlb.h
index 9773014320..a4de317452 100644
--- a/xen/include/asm-x86/flushtlb.h
+++ b/xen/include/asm-x86/flushtlb.h
@@ -123,6 +123,9 @@ void switch_cr3_cr4(unsigned long cr3, unsigned long cr4);
  /* Flush all HVM guests linear TLB (using ASID/VPID) */
 #define FLUSH_GUESTS_TLB 0x4000
 
+#define FLUSH_TLB_FLAGS_MASK (FLUSH_TLB | FLUSH_TLB_GLOBAL | FLUSH_VA_VALID | \
+                              FLUSH_ORDER_MASK)
+
 /* Flush local TLBs/caches. */
 unsigned int flush_area_local(const void *va, unsigned int flags);
 #define flush_local(flags) flush_area_local(NULL, flags)
diff --git a/xen/include/asm-x86/guest/hypervisor.h b/xen/include/asm-x86/guest/hypervisor.h
index 432e57c2a0..48d54735d2 100644
--- a/xen/include/asm-x86/guest/hypervisor.h
+++ b/xen/include/asm-x86/guest/hypervisor.h
@@ -35,7 +35,7 @@ struct hypervisor_ops {
     /* Fix up e820 map */
     void (*e820_fixup)(struct e820map *e820);
     /* L0 assisted TLB flush */
-    int (*flush_tlb)(const cpumask_t *mask, const void *va, unsigned int order);
+    int (*flush_tlb)(const cpumask_t *mask, const void *va, unsigned int flags);
 };
 
 #ifdef CONFIG_GUEST
@@ -48,11 +48,11 @@ void hypervisor_e820_fixup(struct e820map *e820);
 /*
  * L0 assisted TLB flush.
  * mask: cpumask of the dirty vCPUs that should be flushed.
- * va: linear address to flush, or NULL for global flushes.
- * order: order of the linear address pointed by va.
+ * va: linear address to flush, or NULL for entire address space.
+ * flags: flags for flushing, including the order of va.
  */
 int hypervisor_flush_tlb(const cpumask_t *mask, const void *va,
-                         unsigned int order);
+                         unsigned int flags);
 
 #else
 
@@ -65,7 +65,7 @@ static inline int hypervisor_ap_setup(void) { return 0; }
 static inline void hypervisor_resume(void) { ASSERT_UNREACHABLE(); }
 static inline void hypervisor_e820_fixup(struct e820map *e820) {}
 static inline int hypervisor_flush_tlb(const cpumask_t *mask, const void *va,
-                                       unsigned int order)
+                                       unsigned int flags)
 {
     return -ENOSYS;
 }
-- 
2.20.1


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