nestedhap: Change nested p2m's walker to vendor-specific

EPT and NPT adopts differnt formats for each-level entry,
so change the walker functions to vendor-specific.

Signed-off-by: Zhang Xiantao <xiantao.zhang@intel.com>
Acked-by: Tim Deegan <tim@xen.org>
Acked-by: Jun Nakajima <jun.nakajima@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Committed-by: Jan Beulich <jbeulich@suse.com>

2 files changed, 31 insertions, 0 deletions

diff --git a/xen/arch/x86/hvm/svm/nestedsvm.c b/xen/arch/x86/hvm/svm/nestedsvm.c
index ed0faa640f..0a7da95b86 100644
--- a/xen/arch/x86/hvm/svm/nestedsvm.c
+++ b/xen/arch/x86/hvm/svm/nestedsvm.c
@@ -1171,6 +1171,36 @@ nsvm_vmcb_hap_enabled(struct vcpu *v)
     return vcpu_nestedsvm(v).ns_hap_enabled;
 }
 
+/* This function uses L2_gpa to walk the P2M page table in L1. If the
+ * walk is successful, the translated value is returned in
+ * L1_gpa. The result value tells what to do next.
+ */
+int
+nsvm_hap_walk_L1_p2m(struct vcpu *v, paddr_t L2_gpa, paddr_t *L1_gpa,
+                     unsigned int *page_order,
+                     bool_t access_r, bool_t access_w, bool_t access_x)
+{
+    uint32_t pfec;
+    unsigned long nested_cr3, gfn;
+
+    nested_cr3 = nhvm_vcpu_p2m_base(v);
+
+    pfec = PFEC_user_mode | PFEC_page_present;
+    if ( access_w )
+        pfec |= PFEC_write_access;
+    if ( access_x )
+        pfec |= PFEC_insn_fetch;
+
+    /* Walk the guest-supplied NPT table, just as if it were a pagetable */
+    gfn = paging_ga_to_gfn_cr3(v, nested_cr3, L2_gpa, &pfec, page_order);
+
+    if ( gfn == INVALID_GFN )
+        return NESTEDHVM_PAGEFAULT_INJECT;
+
+    *L1_gpa = (gfn << PAGE_SHIFT) + (L2_gpa & ~PAGE_MASK);
+    return NESTEDHVM_PAGEFAULT_DONE;
+}
+
 enum hvm_intblk nsvm_intr_blocked(struct vcpu *v)
 {
     struct nestedsvm *svm = &vcpu_nestedsvm(v);
diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c
index 2c8504a881..acd2d4953e 100644
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -2008,6 +2008,7 @@ static struct hvm_function_table __read_mostly svm_function_table = {
     .nhvm_vmcx_guest_intercepts_trap = nsvm_vmcb_guest_intercepts_trap,
     .nhvm_vmcx_hap_enabled = nsvm_vmcb_hap_enabled,
     .nhvm_intr_blocked = nsvm_intr_blocked,
+    .nhvm_hap_walk_L1_p2m = nsvm_hap_walk_L1_p2m,
 };
 
 void svm_vmexit_handler(struct cpu_user_regs *regs)