Merge tag 'for-linus-5.11-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git...

Pull xen fixes from Juergen Gross:

 - A fix for a regression introduced in 5.11 resulting in Xen dom0
   having problems to correctly initialize Xenstore.

 - A fix for avoiding WARN splats when booting as Xen dom0 with
   CONFIG_AMD_MEM_ENCRYPT enabled due to a missing trap handler for the
   #VC exception (even if the handler should never be called).

 - A fix for the Xen bklfront driver adapting to the correct but
   unexpected behavior of new qemu.

* tag 'for-linus-5.11-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen: avoid warning in Xen pv guest with CONFIG_AMD_MEM_ENCRYPT enabled
  xen: Fix XenStore initialisation for XS_LOCAL
  xen-blkfront: allow discard-* nodes to be optional

diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 247a60a..f656aab 100644 (file)
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -613,6 +613,7 @@ DECLARE_IDTENTRY_VC(X86_TRAP_VC,    exc_vmm_communication);
 
 #ifdef CONFIG_XEN_PV
 DECLARE_IDTENTRY_XENCB(X86_TRAP_OTHER, exc_xen_hypervisor_callback);
+DECLARE_IDTENTRY_RAW(X86_TRAP_OTHER,   exc_xen_unknown_trap);
 #endif
 
 /* Device interrupts common/spurious */

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 4409306..9a5a50c 100644 (file)
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -583,6 +583,13 @@ DEFINE_IDTENTRY_RAW(xenpv_exc_debug)
                exc_debug(regs);
 }
 
+DEFINE_IDTENTRY_RAW(exc_xen_unknown_trap)
+{
+       /* This should never happen and there is no way to handle it. */
+       pr_err("Unknown trap in Xen PV mode.");
+       BUG();
+}
+
 struct trap_array_entry {
        void (*orig)(void);
        void (*xen)(void);
@@ -631,6 +638,7 @@ static bool __ref get_trap_addr(void **addr, unsigned int ist)
 {
        unsigned int nr;
        bool ist_okay = false;
+       bool found = false;
 
        /*
         * Replace trap handler addresses by Xen specific ones.
@@ -645,6 +653,7 @@ static bool __ref get_trap_addr(void **addr, unsigned int ist)
                if (*addr == entry->orig) {
                        *addr = entry->xen;
                        ist_okay = entry->ist_okay;
+                       found = true;
                        break;
                }
        }
@@ -655,9 +664,13 @@ static bool __ref get_trap_addr(void **addr, unsigned int ist)
                nr = (*addr - (void *)early_idt_handler_array[0]) /
                     EARLY_IDT_HANDLER_SIZE;
                *addr = (void *)xen_early_idt_handler_array[nr];
+               found = true;
        }
 
-       if (WARN_ON(ist != 0 && !ist_okay))
+       if (!found)
+               *addr = (void *)xen_asm_exc_xen_unknown_trap;
+
+       if (WARN_ON(found && ist != 0 && !ist_okay))
                return false;
 
        return true;

diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
index 1cb0e84..53cf8aa 100644 (file)
--- a/arch/x86/xen/xen-asm.S
+++ b/arch/x86/xen/xen-asm.S
@@ -178,6 +178,7 @@ xen_pv_trap asm_exc_simd_coprocessor_error
 #ifdef CONFIG_IA32_EMULATION
 xen_pv_trap entry_INT80_compat
 #endif
+xen_pv_trap asm_exc_xen_unknown_trap
 xen_pv_trap asm_exc_xen_hypervisor_callback
 
        __INIT

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 5265975..e1c6798 100644 (file)
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -945,7 +945,8 @@ static void blkif_set_queue_limits(struct blkfront_info *info)
        if (info->feature_discard) {
                blk_queue_flag_set(QUEUE_FLAG_DISCARD, rq);
                blk_queue_max_discard_sectors(rq, get_capacity(gd));
-               rq->limits.discard_granularity = info->discard_granularity;
+               rq->limits.discard_granularity = info->discard_granularity ?:
+                                                info->physical_sector_size;
                rq->limits.discard_alignment = info->discard_alignment;
                if (info->feature_secdiscard)
                        blk_queue_flag_set(QUEUE_FLAG_SECERASE, rq);
@@ -2179,19 +2180,12 @@ static void blkfront_closing(struct blkfront_info *info)
 
 static void blkfront_setup_discard(struct blkfront_info *info)
 {
-       int err;
-       unsigned int discard_granularity;
-       unsigned int discard_alignment;
-
        info->feature_discard = 1;
-       err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
-               "discard-granularity", "%u", &discard_granularity,
-               "discard-alignment", "%u", &discard_alignment,
-               NULL);
-       if (!err) {
-               info->discard_granularity = discard_granularity;
-               info->discard_alignment = discard_alignment;
-       }
+       info->discard_granularity = xenbus_read_unsigned(info->xbdev->otherend,
+                                                        "discard-granularity",
+                                                        0);
+       info->discard_alignment = xenbus_read_unsigned(info->xbdev->otherend,
+                                                      "discard-alignment", 0);
        info->feature_secdiscard =
                !!xenbus_read_unsigned(info->xbdev->otherend, "discard-secure",
                                       0);

diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index c8f0282..18ffd05 100644 (file)
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -714,6 +714,23 @@ static bool xs_hvm_defer_init_for_callback(void)
 #endif
 }
 
+static int xenbus_probe_thread(void *unused)
+{
+       DEFINE_WAIT(w);
+
+       /*
+        * We actually just want to wait for *any* trigger of xb_waitq,
+        * and run xenbus_probe() the moment it occurs.
+        */
+       prepare_to_wait(&xb_waitq, &w, TASK_INTERRUPTIBLE);
+       schedule();
+       finish_wait(&xb_waitq, &w);
+
+       DPRINTK("probing");
+       xenbus_probe();
+       return 0;
+}
+
 static int __init xenbus_probe_initcall(void)
 {
        /*
@@ -725,6 +742,20 @@ static int __init xenbus_probe_initcall(void)
             !xs_hvm_defer_init_for_callback()))
                xenbus_probe();
 
+       /*
+        * For XS_LOCAL, spawn a thread which will wait for xenstored
+        * or a xenstore-stubdom to be started, then probe. It will be
+        * triggered when communication starts happening, by waiting
+        * on xb_waitq.
+        */
+       if (xen_store_domain_type == XS_LOCAL) {
+               struct task_struct *probe_task;
+
+               probe_task = kthread_run(xenbus_probe_thread, NULL,
+                                        "xenbus_probe");
+               if (IS_ERR(probe_task))
+                       return PTR_ERR(probe_task);
+       }
        return 0;
 }
 device_initcall(xenbus_probe_initcall);