diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index e74df9548a025c2d66b3052f8ac0002695e59498..ff962d4b821e5162415fa06ddf75e8c57d498b51 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -209,6 +209,9 @@ static void __init xen_banner(void)
xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
}
+#define CPUID_THERM_POWER_LEAF 6
+#define APERFMPERF_PRESENT 0
+
static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0;
static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
@@ -242,6 +245,11 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
*dx = cpuid_leaf5_edx_val;
return;
+ case CPUID_THERM_POWER_LEAF:
+ /* Disabling APERFMPERF for kernel usage */
+ maskecx = ~(1 << APERFMPERF_PRESENT);
+ break;
+
case 0xb:
/* Suppress extended topology stuff */
maskebx = 0;
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index ffd08c414e91a7cc9f4a507b4ca3bbad9b823523..64effdc6da9400c09515af384d3d4b94c8efcb50 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -706,6 +706,7 @@ int m2p_add_override(unsigned long mfn, struct page *page,
unsigned long uninitialized_var(address);
unsigned level;
pte_t *ptep = NULL;
+ int ret = 0;
pfn = page_to_pfn(page);
if (!PageHighMem(page)) {
@@ -741,6 +742,24 @@ int m2p_add_override(unsigned long mfn, struct page *page,
list_add(&page->lru, &m2p_overrides[mfn_hash(mfn)]);
spin_unlock_irqrestore(&m2p_override_lock, flags);
+ /* p2m(m2p(mfn)) == mfn: the mfn is already present somewhere in
+ * this domain. Set the FOREIGN_FRAME_BIT in the p2m for the other
+ * pfn so that the following mfn_to_pfn(mfn) calls will return the
+ * pfn from the m2p_override (the backend pfn) instead.
+ * We need to do this because the pages shared by the frontend
+ * (xen-blkfront) can be already locked (lock_page, called by
+ * do_read_cache_page); when the userspace backend tries to use them
+ * with direct_IO, mfn_to_pfn returns the pfn of the frontend, so
+ * do_blockdev_direct_IO is going to try to lock the same pages
+ * again resulting in a deadlock.
+ * As a side effect get_user_pages_fast might not be safe on the
+ * frontend pages while they are being shared with the backend,
+ * because mfn_to_pfn (that ends up being called by GUPF) will
+ * return the backend pfn rather than the frontend pfn. */
+ ret = __get_user(pfn, &machine_to_phys_mapping[mfn]);
+ if (ret == 0 && get_phys_to_machine(pfn) == mfn)
+ set_phys_to_machine(pfn, FOREIGN_FRAME(mfn));
+
return 0;
}
EXPORT_SYMBOL_GPL(m2p_add_override);
@@ -752,6 +771,7 @@ int m2p_remove_override(struct page *page, bool clear_pte)
unsigned long uninitialized_var(address);
unsigned level;
pte_t *ptep = NULL;
+ int ret = 0;
pfn = page_to_pfn(page);
mfn = get_phys_to_machine(pfn);
@@ -821,6 +841,22 @@ int m2p_remove_override(struct page *page, bool clear_pte)
} else
set_phys_to_machine(pfn, page->index);
+ /* p2m(m2p(mfn)) == FOREIGN_FRAME(mfn): the mfn is already present
+ * somewhere in this domain, even before being added to the
+ * m2p_override (see comment above in m2p_add_override).
+ * If there are no other entries in the m2p_override corresponding
+ * to this mfn, then remove the FOREIGN_FRAME_BIT from the p2m for
+ * the original pfn (the one shared by the frontend): the backend
+ * cannot do any IO on this page anymore because it has been
+ * unshared. Removing the FOREIGN_FRAME_BIT from the p2m entry of
+ * the original pfn causes mfn_to_pfn(mfn) to return the frontend
+ * pfn again. */
+ mfn &= ~FOREIGN_FRAME_BIT;
+ ret = __get_user(pfn, &machine_to_phys_mapping[mfn]);
+ if (ret == 0 && get_phys_to_machine(pfn) == FOREIGN_FRAME(mfn) &&
+ m2p_find_override(mfn) == NULL)
+ set_phys_to_machine(pfn, mfn);
+
return 0;
}
EXPORT_SYMBOL_GPL(m2p_remove_override);
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 3ebba0753d3876b887875aaf53fdd461f544441c..a4790bf22c592326b4b53a80f615e2f2ee658b83 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -371,7 +371,8 @@ char * __init xen_memory_setup(void)
populated = xen_populate_chunk(map, memmap.nr_entries,
max_pfn, &last_pfn, xen_released_pages);
- extra_pages += (xen_released_pages - populated);
+ xen_released_pages -= populated;
+ extra_pages += xen_released_pages;
if (last_pfn > max_pfn) {
max_pfn = min(MAX_DOMAIN_PAGES, last_pfn);
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index d3d91dae065cfdceb3c6b4918c27ad6c252caf33..944eaeb8e0cff62b89ea735b0d98e167ddd806d0 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -214,24 +214,24 @@ static int xen_hvm_console_init(void)
/* already configured */
if (info->intf != NULL)
return 0;
-
+ /*
+ * If the toolstack (or the hypervisor) hasn't set these values, the
+ * default value is 0. Even though mfn = 0 and evtchn = 0 are
+ * theoretically correct values, in practice they never are and they
+ * mean that a legacy toolstack hasn't initialized the pv console correctly.
+ */
r = hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN, &v);
- if (r < 0) {
- kfree(info);
- return -ENODEV;
- }
+ if (r < 0 || v == 0)
+ goto err;
info->evtchn = v;
- hvm_get_parameter(HVM_PARAM_CONSOLE_PFN, &v);
- if (r < 0) {
- kfree(info);
- return -ENODEV;
- }
+ v = 0;
+ r = hvm_get_parameter(HVM_PARAM_CONSOLE_PFN, &v);
+ if (r < 0 || v == 0)
+ goto err;
mfn = v;
info->intf = ioremap(mfn << PAGE_SHIFT, PAGE_SIZE);
- if (info->intf == NULL) {
- kfree(info);
- return -ENODEV;
- }
+ if (info->intf == NULL)
+ goto err;
info->vtermno = HVC_COOKIE;
spin_lock(&xencons_lock);
@@ -239,6 +239,9 @@ static int xen_hvm_console_init(void)
spin_unlock(&xencons_lock);
return 0;
+err:
+ kfree(info);
+ return -ENODEV;
}
static int xen_pv_console_init(void)
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 6908e4ce2a0d69aa67ca0e11251d834770bbd68c..7595581d032cc9d9c5a7f04ee12b861dc76051ee 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -827,6 +827,9 @@ int bind_evtchn_to_irq(unsigned int evtchn)
handle_edge_irq, "event");
xen_irq_info_evtchn_init(irq, evtchn);
+ } else {
+ struct irq_info *info = info_for_irq(irq);
+ WARN_ON(info == NULL || info->type != IRQT_EVTCHN);
}
out:
@@ -862,6 +865,9 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
xen_irq_info_ipi_init(cpu, irq, evtchn, ipi);
bind_evtchn_to_cpu(evtchn, cpu);
+ } else {
+ struct irq_info *info = info_for_irq(irq);
+ WARN_ON(info == NULL || info->type != IRQT_IPI);
}
out:
@@ -939,6 +945,9 @@ int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
xen_irq_info_virq_init(cpu, irq, evtchn, virq);
bind_evtchn_to_cpu(evtchn, cpu);
+ } else {
+ struct irq_info *info = info_for_irq(irq);
+ WARN_ON(info == NULL || info->type != IRQT_VIRQ);
}
out:
diff --git a/drivers/xen/pci.c b/drivers/xen/pci.c
index b84bf0b6cc34c4fd34bfd35015bd8057f0ddf6b9..18fff88254ebd9bd9e4c76b1df63ecf40dc4e139 100644
--- a/drivers/xen/pci.c
+++ b/drivers/xen/pci.c
@@ -59,7 +59,7 @@ static int xen_add_device(struct device *dev)
#ifdef CONFIG_ACPI
handle = DEVICE_ACPI_HANDLE(&pci_dev->dev);
- if (!handle)
+ if (!handle && pci_dev->bus->bridge)
handle = DEVICE_ACPI_HANDLE(pci_dev->bus->bridge);
#ifdef CONFIG_PCI_IOV
if (!handle && pci_dev->is_virtfn)