Re: [Xen-devel] [PATCH v2 3/7] xen/vm-events: Move monitor_domctl to common-side.

[Tamas K Lengyel <tamas@xxxxxxxxxxxxx>]

On Wed, Feb 10, 2016 at 8:52 AM, Corneliu ZUZU <czuzu@xxxxxxxxxxxxxxx> wrote:

1. Kconfig:
 * Added Kconfigs for common monitor vm-events:
 # see files: common/Kconfig, x86/Kconfig
  HAS_VM_EVENT_WRITE_CTRLREG
  HAS_VM_EVENT_SINGLESTEP
  HAS_VM_EVENT_SOFTWARE_BREAKPOINT
  HAS_VM_EVENT_GUEST_REQUEST

2. Moved monitor_domctl from arch-side to common-side
 2.1. Moved arch/x86/monitor.c to common/monitor.c
  # see files: arch/x86/Makefile, xen/common/Makefile, xen/common/monitor.c
  # changes:
    - removed status_check (we would have had to duplicate it in X86
      arch_monitor_domctl_event otherwise)
    - moved get_capabilities to arch-side (arch_monitor_get_capabilities)
    - moved XEN_DOMCTL_MONITOR_OP_EMULATE_EACH_REP to arch-side (see
      arch_monitor_domctl_op)
    - put XEN_DOMCTL_MONITOR_EVENT_MOV_TO_MSR to x86-side (see
      arch_monitor_domctl_event)
    - surrounded switch cases w/ CONFIG_HAS_VM_EVENT_*

 2.2. Moved asm-x86/monitor.h to xen/monitor.h
  # see files: arch/x86/hvm/event.c, arch/x86/hvm/hvm.c,
        Âarch/x86/hvm/vmx/vmx.c, xen/common/domctl.c

 2.3. Removed asm-arm/monitor.h (no longer needed)

3. Added x86/monitor_x86.c => will rename in next commit to monitor.c (not done
in this commit to avoid git seeing this as being the modified old monitor.c =>
keeping the same name would have rendered an unnecessarily bulky diff)
  # see files: arch/x86/Makefile
  # implements X86-side arch_monitor_domctl_event

4. Added asm-x86/monitor_arch.h, asm-arm/monitor_arch.h (renamed to
monitor.h in next commit, reason is the same as @ (3.).
  # define/implement: arch_monitor_get_capabilities, arch_monitor_domctl_op
    and arch_monitor_domctl_event

So these commit messages are not very good IMHO. Rather then just summarizing what the patch does you should describe why the patch is needed in the first place. Usually for longer series having a cover page is also helpful to outline how the patches in the series fit together.

Â

Signed-off-by: Corneliu ZUZU <czuzu@xxxxxxxxxxxxxxx>
---
Âxen/arch/x86/Kconfig               | Â4 +
Âxen/arch/x86/Makefile              Â| Â2 +-
Âxen/arch/x86/hvm/event.c             | Â2 +-
Âxen/arch/x86/hvm/hvm.c              | Â2 +-
Âxen/arch/x86/hvm/vmx/vmx.c            | Â2 +-
Âxen/arch/x86/monitor_x86.c            | 72 ++++++++
Âxen/common/Kconfig                | 20 +++
Âxen/common/Makefile               Â| Â1 +
Âxen/common/domctl.c               Â| Â2 +-
Âxen/{arch/x86 => common}/monitor.c        | 195 +++++++++-------------
Âxen/include/asm-arm/{monitor.h => monitor_arch.h} |Â 34 +++-
Âxen/include/asm-x86/monitor_arch.h        | 74 ++++++++
Âxen/include/{asm-x86 => xen}/monitor.h      | 17 +-
Â13 files changed, 293 insertions(+), 134 deletions(-)
Âcreate mode 100644 xen/arch/x86/monitor_x86.c
Ârename xen/{arch/x86 => common}/monitor.c (44%)
Ârename xen/include/asm-arm/{monitor.h => monitor_arch.h} (46%)
Âcreate mode 100644 xen/include/asm-x86/monitor_arch.h
Ârename xen/include/{asm-x86 => xen}/monitor.h (74%)

diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
index 3a90f47..e46be1b 100644
--- a/xen/arch/x86/Kconfig
+++ b/xen/arch/x86/Kconfig
@@ -14,6 +14,10 @@ config X86
    select HAS_MEM_ACCESS
    select HAS_MEM_PAGING
    select HAS_MEM_SHARING
+Â Â Â Âselect HAS_VM_EVENT_WRITE_CTRLREG

You mentioned in the previous revision of this series that currently you only have plans to implement write_ctrleg and guest_request events for ARM. I think singlestep and software_breakpoint should not be moved to common without a clear plan to have those implemented. Now, if you were to include the implementation of write_ctrlreg and guest_request in this series and leave the others in x86 as they are now, I don't think there would be any reason to have these Kconfig options present at all.

Â

+Â Â Â Âselect HAS_VM_EVENT_SINGLESTEP
+Â Â Â Âselect HAS_VM_EVENT_SOFTWARE_BREAKPOINT
+Â Â Â Âselect HAS_VM_EVENT_GUEST_REQUEST
    select HAS_NS16550
    select HAS_PASSTHROUGH
    select HAS_PCI
diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile
index 8e6e901..6e80cf0 100644
--- a/xen/arch/x86/Makefile
+++ b/xen/arch/x86/Makefile
@@ -36,7 +36,7 @@ obj-y += microcode_intel.o
Â# This must come after the vendor specific files.
Âobj-y += microcode.o
Âobj-y += mm.o x86_64/mm.o
-obj-y += monitor.o
+obj-y += monitor_x86.o
Âobj-y += mpparse.o
Âobj-y += nmi.o
Âobj-y += numa.o
diff --git a/xen/arch/x86/hvm/event.c b/xen/arch/x86/hvm/event.c
index e3444db..04faa72 100644
--- a/xen/arch/x86/hvm/event.c
+++ b/xen/arch/x86/hvm/event.c
@@ -23,8 +23,8 @@

Â#include <xen/vm_event.h>
Â#include <xen/paging.h>
+#include <xen/monitor.h>
Â#include <asm/hvm/event.h>
-#include <asm/monitor.h>
Â#include <asm/altp2m.h>
Â#include <public/vm_event.h>

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 930d0e3..e93a648 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -32,6 +32,7 @@
Â#include <xen/guest_access.h>
Â#include <xen/event.h>
Â#include <xen/paging.h>
+#include <xen/monitor.h>
Â#include <xen/cpu.h>
Â#include <xen/wait.h>
Â#include <xen/mem_access.h>
@@ -51,7 +52,6 @@
Â#include <asm/traps.h>
Â#include <asm/mc146818rtc.h>
Â#include <asm/mce.h>
-#include <asm/monitor.h>
Â#include <asm/hvm/hvm.h>
Â#include <asm/hvm/vpt.h>
Â#include <asm/hvm/support.h>
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index cf0e642..be67b60 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -25,6 +25,7 @@
Â#include <xen/domain_page.h>
Â#include <xen/hypercall.h>
Â#include <xen/perfc.h>
+#include <xen/monitor.h>
Â#include <asm/current.h>
Â#include <asm/io.h>
Â#include <asm/iocap.h>
@@ -57,7 +58,6 @@
Â#include <asm/hvm/nestedhvm.h>
Â#include <asm/altp2m.h>
Â#include <asm/event.h>
-#include <asm/monitor.h>
Â#include <public/arch-x86/cpuid.h>

Âstatic bool_t __initdata opt_force_ept;
diff --git a/xen/arch/x86/monitor_x86.c b/xen/arch/x86/monitor_x86.c
new file mode 100644
index 0000000..d19fd15
--- /dev/null
+++ b/xen/arch/x86/monitor_x86.c
@@ -0,0 +1,72 @@
+/*
+ * arch/x86/monitor_x86.c
+ *
+ * Arch-specific monitor_op domctl handler.
+ *
+ * Copyright (c) 2015 Tamas K Lengyel (tamas@xxxxxxxxxxxxx)
+ * Copyright (c) 2016, Bitdefender S.R.L.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <asm/monitor_arch.h>
+
+bool_t arch_monitor_domctl_event(struct domain *d,
+Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Âstruct xen_domctl_monitor_op *mop,
+Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Âint *rc)
+{
+Â Â struct arch_domain *ad = &d->arch;
+Â Â bool_t requested_status = (XEN_DOMCTL_MONITOR_OP_ENABLE == mop->op);
+
+Â Â switch ( mop->event )
+Â Â {
+Â Â Â Â case XEN_DOMCTL_MONITOR_EVENT_MOV_TO_MSR:
+Â Â Â Â {
+Â Â Â Â Â Â bool_t old_status = ad->monitor.mov_to_msr_enabled;
+
+Â Â Â Â Â Â if ( unlikely(old_status == requested_status) )
+Â Â Â Â Â Â Â Â return -EEXIST;

This function is defined to return bool_t and yet you are returning non-boolean error codes. I think it would be better if this function just had a single rc instead of two (not passing one rc as a pointer on input).

Â

+
+Â Â Â Â Â Â if ( XEN_DOMCTL_MONITOR_OP_ENABLE == mop->op &&
+Â Â Â Â Â Â Â Â Âmop->u.mov_to_msr.extended_capture &&
+Â Â Â Â Â Â Â Â Â!hvm_enable_msr_exit_interception(d) )
+Â Â Â Â Â Â Â Â return -EOPNOTSUPP;
+
+Â Â Â Â Â Â domain_pause(d);
+
+Â Â Â Â Â Â if ( XEN_DOMCTL_MONITOR_OP_ENABLE == mop->op &&
+Â Â Â Â Â Â Â Â Âmop->u.mov_to_msr.extended_capture )
+Â Â Â Â Â Â Â Â ad->monitor.mov_to_msr_extended = 1;
+Â Â Â Â Â Â else
+Â Â Â Â Â Â Â Â ad->monitor.mov_to_msr_extended = 0;
+
+Â Â Â Â Â Â ad->monitor.mov_to_msr_enabled = !old_status;
+Â Â Â Â Â Â domain_unpause(d);
+Â Â Â Â Â Â break;
+Â Â Â Â }
+
+Â Â Â Â default:
+Â Â Â Â Â Â return 0;
+Â Â }
+
+Â Â return 1;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */

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