[Xen-devel] [PATCH RFC 05/12] x86/np2m: add np2m_generation

[Sergey Dyasli <sergey.dyasli@xxxxxxxxxx>]

Add np2m_generation variable to both p2m_domain and nestedvcpu.

np2m's generation will be incremented each time the np2m is flushed.
This will allow to detect if a nested vcpu has the stale np2m.

Signed-off-by: Sergey Dyasli <sergey.dyasli@xxxxxxxxxx>
---
 xen/arch/x86/hvm/nestedhvm.c   | 1 +
 xen/arch/x86/mm/p2m.c          | 3 +++
 xen/include/asm-x86/hvm/vcpu.h | 1 +
 xen/include/asm-x86/p2m.h      | 1 +
 4 files changed, 6 insertions(+)

diff --git a/xen/arch/x86/hvm/nestedhvm.c b/xen/arch/x86/hvm/nestedhvm.c
index f2f7469d86..32b8acca6a 100644
--- a/xen/arch/x86/hvm/nestedhvm.c
+++ b/xen/arch/x86/hvm/nestedhvm.c
@@ -56,6 +56,7 @@ nestedhvm_vcpu_reset(struct vcpu *v)
     nv->nv_vvmcxaddr = INVALID_PADDR;
     nv->nv_flushp2m = 0;
     nv->nv_p2m = NULL;
+    nv->np2m_generation = 0;
 
     hvm_asid_flush_vcpu_asid(&nv->nv_n2asid);
 
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index e7bd0dbac8..4fc2d94b46 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -73,6 +73,7 @@ static int p2m_initialise(struct domain *d, struct p2m_domain 
*p2m)
     p2m->p2m_class = p2m_host;
 
     p2m->np2m_base = P2M_BASE_EADDR;
+    p2m->np2m_generation = 0;
 
     for ( i = 0; i < ARRAY_SIZE(p2m->pod.mrp.list); ++i )
         p2m->pod.mrp.list[i] = gfn_x(INVALID_GFN);
@@ -1735,6 +1736,7 @@ p2m_flush_table_locked(struct p2m_domain *p2m)
 
     /* This is no longer a valid nested p2m for any address space */
     p2m->np2m_base = P2M_BASE_EADDR;
+    p2m->np2m_generation++;
 
     /* Make sure nobody else is using this p2m table */
     nestedhvm_vmcx_flushtlb(p2m);
@@ -1811,6 +1813,7 @@ static void assign_np2m(struct vcpu *v, struct p2m_domain 
*p2m)
 
     nv->nv_flushp2m = 0;
     nv->nv_p2m = p2m;
+    nv->np2m_generation = p2m->np2m_generation;
     cpumask_set_cpu(v->processor, p2m->dirty_cpumask);
 }
 
diff --git a/xen/include/asm-x86/hvm/vcpu.h b/xen/include/asm-x86/hvm/vcpu.h
index 6c54773f1c..91651581db 100644
--- a/xen/include/asm-x86/hvm/vcpu.h
+++ b/xen/include/asm-x86/hvm/vcpu.h
@@ -115,6 +115,7 @@ struct nestedvcpu {
 
     bool_t nv_flushp2m; /* True, when p2m table must be flushed */
     struct p2m_domain *nv_p2m; /* used p2m table for this vcpu */
+    uint64_t np2m_generation;
 
     struct hvm_vcpu_asid nv_n2asid;
 
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index cc1bab9eb7..eedc7fd412 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -209,6 +209,7 @@ struct p2m_domain {
      * to set it to any other value. */
 #define P2M_BASE_EADDR     (~0ULL)
     uint64_t           np2m_base;
+    uint64_t           np2m_generation;
 
     /* Nested p2ms: linked list of n2pms allocated to this domain. 
      * The host p2m hasolds the head of the list and the np2ms are 
-- 
2.11.0


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