[Xen-devel] [PATCH] [IOMMU] dynamic VTd page table for HVM guest

["Zhai, Edwin" <edwin.zhai@xxxxxxxxx>]

This patch makes HVM's VTd page table dynamic just like what PV guest
does, so that avoid the overhead of maintaining page table until a PCI
device is truly assigned to the HVM guest.

Signed-Off-By: Zhai, Edwin <edwin.zhai@xxxxxxxxx>

Wei,
This patch also remove some duplicated codes on your side, and is safe
in theory. You can have a check.
Thanks,


--
best rgds,
edwin

Index: hv/xen/arch/ia64/xen/domain.c
===================================================================
--- hv.orig/xen/arch/ia64/xen/domain.c
+++ hv/xen/arch/ia64/xen/domain.c
@@ -669,7 +669,7 @@ void arch_domain_destroy(struct domain *
                free_xenheap_pages(d->shared_info,
                                   get_order_from_shift(XSI_SHIFT));
 
-       if ( iommu_enabled && (is_hvm_domain(d) || need_iommu(d)) )     {
+       if ( iommu_enabled && need_iommu(d) )   {
                pci_release_devices(d);
                iommu_domain_destroy(d);
        }
Index: hv/xen/arch/ia64/xen/mm.c
===================================================================
--- hv.orig/xen/arch/ia64/xen/mm.c
+++ hv/xen/arch/ia64/xen/mm.c
@@ -1479,7 +1479,7 @@ zap_domain_page_one(struct domain *d, un
     if(!mfn_valid(mfn))
         return;
 
-    if ( iommu_enabled && (is_hvm_domain(d) || need_iommu(d)) ){
+    if ( iommu_enabled && need_iommu(d) ){
         int i, j;
         j = 1 << (PAGE_SHIFT-PAGE_SHIFT_4K);
         for(i = 0 ; i < j; i++)
@@ -2885,7 +2885,7 @@ __guest_physmap_add_page(struct domain *
     smp_mb();
     assign_domain_page_replace(d, gpfn << PAGE_SHIFT, mfn,
                                ASSIGN_writable | ASSIGN_pgc_allocated);
-    if ( iommu_enabled && (is_hvm_domain(d) || need_iommu(d)) ){
+    if ( iommu_enabled && need_iommu(d) ){
         int i, j;
         j = 1 << (PAGE_SHIFT-PAGE_SHIFT_4K);
         for(i = 0 ; i < j; i++)
Index: hv/xen/arch/x86/mm/hap/p2m-ept.c
===================================================================
--- hv.orig/xen/arch/x86/mm/hap/p2m-ept.c
+++ hv/xen/arch/x86/mm/hap/p2m-ept.c
@@ -282,7 +282,7 @@ out:
     ept_sync_domain(d);
 
     /* Now the p2m table is not shared with vt-d page table */
-    if ( iommu_enabled && is_hvm_domain(d) && need_modify_vtd_table )
+    if ( iommu_enabled && need_iommu(d) && need_modify_vtd_table )
     {
         if ( p2mt == p2m_ram_rw )
         {
Index: hv/xen/arch/x86/mm/p2m.c
===================================================================
--- hv.orig/xen/arch/x86/mm/p2m.c
+++ hv/xen/arch/x86/mm/p2m.c
@@ -1199,7 +1199,7 @@ p2m_set_entry(struct domain *d, unsigned
          && (gfn + (1UL << page_order) - 1 > d->arch.p2m->max_mapped_pfn) )
         d->arch.p2m->max_mapped_pfn = gfn + (1UL << page_order) - 1;
 
-    if ( iommu_enabled && (is_hvm_domain(d) || need_iommu(d)) )
+    if ( iommu_enabled && need_iommu(d) )
     {
         if ( p2mt == p2m_ram_rw )
             for ( i = 0; i < (1UL << page_order); i++ )
Index: hv/xen/drivers/passthrough/amd/iommu_map.c
===================================================================
--- hv.orig/xen/drivers/passthrough/amd/iommu_map.c
+++ hv/xen/drivers/passthrough/amd/iommu_map.c
@@ -555,58 +555,6 @@ int amd_iommu_reserve_domain_unity_map(
     return 0;
 }
 
-int amd_iommu_sync_p2m(struct domain *d)
-{
-    unsigned long mfn, gfn;
-    u64 iommu_l2e;
-    struct page_info *page;
-    struct hvm_iommu *hd;
-    int iw = IOMMU_IO_WRITE_ENABLED;
-    int ir = IOMMU_IO_READ_ENABLED;
-
-    if ( !is_hvm_domain(d) )
-        return 0;
-
-    hd = domain_hvm_iommu(d);
-
-    spin_lock(&hd->mapping_lock);
-
-    if ( hd->p2m_synchronized )
-        goto out;
-
-    spin_lock(&d->page_alloc_lock);
-
-    page_list_for_each ( page, &d->page_list )
-    {
-        mfn = page_to_mfn(page);
-        gfn = get_gpfn_from_mfn(mfn);
-
-        if ( gfn == INVALID_M2P_ENTRY )
-            continue;
-
-        iommu_l2e = iommu_l2e_from_pfn(hd->root_table, hd->paging_mode, gfn);
-
-        if ( iommu_l2e == 0 )
-        {
-            spin_unlock(&d->page_alloc_lock);
-            spin_unlock(&hd->mapping_lock);
-            amd_iov_error("Invalid IO pagetable entry gfn = %lx\n", gfn);
-            domain_crash(d);
-            return -EFAULT;
-        }
-
-        set_iommu_l1e_present(iommu_l2e, gfn, (u64)mfn << PAGE_SHIFT, iw, ir);
-    }
-
-    spin_unlock(&d->page_alloc_lock);
-
-    hd->p2m_synchronized = 1;
-
-out:
-    spin_unlock(&hd->mapping_lock);
-    return 0;
-}
-
 void invalidate_all_iommu_pages(struct domain *d)
 {
     u32 cmd[4], entry;
Index: hv/xen/drivers/passthrough/amd/pci_amd_iommu.c
===================================================================
--- hv.orig/xen/drivers/passthrough/amd/pci_amd_iommu.c
+++ hv/xen/drivers/passthrough/amd/pci_amd_iommu.c
@@ -311,8 +311,6 @@ static int amd_iommu_assign_device(struc
     int bdf = (bus << 8) | devfn;
     int req_id = ivrs_mappings[bdf].dte_requestor_id;
 
-    amd_iommu_sync_p2m(d);
-
     if ( ivrs_mappings[req_id].unity_map_enable )
     {
         amd_iommu_reserve_domain_unity_map(
Index: hv/xen/drivers/passthrough/iommu.c
===================================================================
--- hv.orig/xen/drivers/passthrough/iommu.c
+++ hv/xen/drivers/passthrough/iommu.c
@@ -137,7 +137,7 @@ int assign_device(struct domain *d, u8 b
     if ( (rc = hd->platform_ops->assign_device(d, bus, devfn)) )
         goto done;
 
-    if ( has_arch_pdevs(d) && !is_hvm_domain(d) && !need_iommu(d) )
+    if ( has_arch_pdevs(d) && !need_iommu(d) )
     {
         d->need_iommu = 1;
         rc = iommu_populate_page_table(d);
@@ -184,7 +184,7 @@ void iommu_domain_destroy(struct domain 
     if ( !iommu_enabled || !hd->platform_ops )
         return;
 
-    if ( !is_hvm_domain(d) && !need_iommu(d)  )
+    if ( !need_iommu(d)  )
         return;
 
     if ( need_iommu(d) )
Index: hv/xen/drivers/passthrough/pci.c
===================================================================
--- hv.orig/xen/drivers/passthrough/pci.c
+++ hv/xen/drivers/passthrough/pci.c
@@ -202,7 +202,7 @@ static void pci_clean_dpci_irqs(struct d
     if ( !iommu_enabled )
         return;
 
-    if ( !is_hvm_domain(d) && !need_iommu(d) )
+    if ( !need_iommu(d) )
         return;
 
     spin_lock(&d->event_lock);
Index: hv/xen/include/asm-x86/hvm/svm/amd-iommu-proto.h
===================================================================
--- hv.orig/xen/include/asm-x86/hvm/svm/amd-iommu-proto.h
+++ hv/xen/include/asm-x86/hvm/svm/amd-iommu-proto.h
@@ -63,7 +63,6 @@ int amd_iommu_unmap_page(struct domain *
 u64 amd_iommu_get_next_table_from_pte(u32 *entry);
 int amd_iommu_reserve_domain_unity_map(struct domain *domain,
         unsigned long phys_addr, unsigned long size, int iw, int ir);
-int amd_iommu_sync_p2m(struct domain *d);
 void invalidate_all_iommu_pages(struct domain *d);
 
 /* device table functions */
Index: hv/xen/include/xen/sched.h
===================================================================
--- hv.orig/xen/include/xen/sched.h
+++ hv/xen/include/xen/sched.h
@@ -557,7 +557,7 @@ uint64_t get_cpu_idle_time(unsigned int 
 
 #define is_hvm_domain(d) ((d)->is_hvm)
 #define is_hvm_vcpu(v)   (is_hvm_domain(v->domain))
-#define need_iommu(d)    ((d)->need_iommu && !(d)->is_hvm)
+#define need_iommu(d)    ((d)->need_iommu)
 
 void set_vcpu_migration_delay(unsigned int delay);
 unsigned int get_vcpu_migration_delay(void);

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