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Diffstat (limited to 'arch/x86/xen/p2m.c')
-rw-r--r--arch/x86/xen/p2m.c62
1 files changed, 51 insertions, 11 deletions
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 8b7f18e20..660b3cfef 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -79,10 +79,14 @@
#include <xen/balloon.h>
#include <xen/grant_table.h>
-#include "p2m.h"
#include "multicalls.h"
#include "xen-ops.h"
+#define P2M_MID_PER_PAGE (PAGE_SIZE / sizeof(unsigned long *))
+#define P2M_TOP_PER_PAGE (PAGE_SIZE / sizeof(unsigned long **))
+
+#define MAX_P2M_PFN (P2M_TOP_PER_PAGE * P2M_MID_PER_PAGE * P2M_PER_PAGE)
+
#define PMDS_PER_MID_PAGE (P2M_MID_PER_PAGE / PTRS_PER_PTE)
unsigned long *xen_p2m_addr __read_mostly;
@@ -108,6 +112,15 @@ static unsigned long *p2m_identity;
static pte_t *p2m_missing_pte;
static pte_t *p2m_identity_pte;
+/*
+ * Hint at last populated PFN.
+ *
+ * Used to set HYPERVISOR_shared_info->arch.max_pfn so the toolstack
+ * can avoid scanning the whole P2M (which may be sized to account for
+ * hotplugged memory).
+ */
+static unsigned long xen_p2m_last_pfn;
+
static inline unsigned p2m_top_index(unsigned long pfn)
{
BUG_ON(pfn >= MAX_P2M_PFN);
@@ -199,7 +212,8 @@ void __ref xen_build_mfn_list_list(void)
unsigned int level, topidx, mididx;
unsigned long *mid_mfn_p;
- if (xen_feature(XENFEAT_auto_translated_physmap))
+ if (xen_feature(XENFEAT_auto_translated_physmap) ||
+ xen_start_info->flags & SIF_VIRT_P2M_4TOOLS)
return;
/* Pre-initialize p2m_top_mfn to be completely missing */
@@ -260,9 +274,16 @@ void xen_setup_mfn_list_list(void)
BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
- HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list =
- virt_to_mfn(p2m_top_mfn);
- HYPERVISOR_shared_info->arch.max_pfn = xen_max_p2m_pfn;
+ if (xen_start_info->flags & SIF_VIRT_P2M_4TOOLS)
+ HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list = ~0UL;
+ else
+ HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list =
+ virt_to_mfn(p2m_top_mfn);
+ HYPERVISOR_shared_info->arch.max_pfn = xen_p2m_last_pfn;
+ HYPERVISOR_shared_info->arch.p2m_generation = 0;
+ HYPERVISOR_shared_info->arch.p2m_vaddr = (unsigned long)xen_p2m_addr;
+ HYPERVISOR_shared_info->arch.p2m_cr3 =
+ xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir));
}
/* Set up p2m_top to point to the domain-builder provided p2m pages */
@@ -394,6 +415,8 @@ void __init xen_vmalloc_p2m_tree(void)
static struct vm_struct vm;
unsigned long p2m_limit;
+ xen_p2m_last_pfn = xen_max_p2m_pfn;
+
p2m_limit = (phys_addr_t)P2M_LIMIT * 1024 * 1024 * 1024 / PAGE_SIZE;
vm.flags = VM_ALLOC;
vm.size = ALIGN(sizeof(unsigned long) * max(xen_max_p2m_pfn, p2m_limit),
@@ -478,8 +501,12 @@ static pte_t *alloc_p2m_pmd(unsigned long addr, pte_t *pte_pg)
ptechk = lookup_address(vaddr, &level);
if (ptechk == pte_pg) {
+ HYPERVISOR_shared_info->arch.p2m_generation++;
+ wmb(); /* Tools are synchronizing via p2m_generation. */
set_pmd(pmdp,
__pmd(__pa(pte_newpg[i]) | _KERNPG_TABLE));
+ wmb(); /* Tools are synchronizing via p2m_generation. */
+ HYPERVISOR_shared_info->arch.p2m_generation++;
pte_newpg[i] = NULL;
}
@@ -505,7 +532,7 @@ static pte_t *alloc_p2m_pmd(unsigned long addr, pte_t *pte_pg)
*/
static bool alloc_p2m(unsigned long pfn)
{
- unsigned topidx, mididx;
+ unsigned topidx;
unsigned long *top_mfn_p, *mid_mfn;
pte_t *ptep, *pte_pg;
unsigned int level;
@@ -513,9 +540,6 @@ static bool alloc_p2m(unsigned long pfn)
unsigned long addr = (unsigned long)(xen_p2m_addr + pfn);
unsigned long p2m_pfn;
- topidx = p2m_top_index(pfn);
- mididx = p2m_mid_index(pfn);
-
ptep = lookup_address(addr, &level);
BUG_ON(!ptep || level != PG_LEVEL_4K);
pte_pg = (pte_t *)((unsigned long)ptep & ~(PAGE_SIZE - 1));
@@ -527,7 +551,8 @@ static bool alloc_p2m(unsigned long pfn)
return false;
}
- if (p2m_top_mfn) {
+ if (p2m_top_mfn && pfn < MAX_P2M_PFN) {
+ topidx = p2m_top_index(pfn);
top_mfn_p = &p2m_top_mfn[topidx];
mid_mfn = ACCESS_ONCE(p2m_top_mfn_p[topidx]);
@@ -577,10 +602,14 @@ static bool alloc_p2m(unsigned long pfn)
spin_lock_irqsave(&p2m_update_lock, flags);
if (pte_pfn(*ptep) == p2m_pfn) {
+ HYPERVISOR_shared_info->arch.p2m_generation++;
+ wmb(); /* Tools are synchronizing via p2m_generation. */
set_pte(ptep,
pfn_pte(PFN_DOWN(__pa(p2m)), PAGE_KERNEL));
+ wmb(); /* Tools are synchronizing via p2m_generation. */
+ HYPERVISOR_shared_info->arch.p2m_generation++;
if (mid_mfn)
- mid_mfn[mididx] = virt_to_mfn(p2m);
+ mid_mfn[p2m_mid_index(pfn)] = virt_to_mfn(p2m);
p2m = NULL;
}
@@ -590,6 +619,12 @@ static bool alloc_p2m(unsigned long pfn)
free_p2m_page(p2m);
}
+ /* Expanded the p2m? */
+ if (pfn > xen_p2m_last_pfn) {
+ xen_p2m_last_pfn = pfn;
+ HYPERVISOR_shared_info->arch.max_pfn = xen_p2m_last_pfn;
+ }
+
return true;
}
@@ -630,6 +665,11 @@ bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
return true;
}
+ /*
+ * The interface requires atomic updates on p2m elements.
+ * xen_safe_write_ulong() is using __put_user which does an atomic
+ * store via asm().
+ */
if (likely(!xen_safe_write_ulong(xen_p2m_addr + pfn, mfn)))
return true;