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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH V7] vm_event: Allow subscribing to write events for specific MSR-s
Previously, subscribing to MSR write events was an all-or-none
approach, with special cases for introspection MSR-s. This patch
allows the vm_event consumer to specify exactly what MSR-s it is
interested in, and as a side-effect gets rid of the
vmx_introspection_force_enabled_msrs[] special case.
The patch also introduces arch_monitor_init_domain() and
arch_monitor_cleanup_domain(), to do monitor-specific work
(as opposed to the previous way of doing all the setup in
vm_event_init_domain() / vm_event_cleanup_domain()).
This replaces the previously posted "xen: Filter out MSR write
events" patch.
Signed-off-by: Razvan Cojocaru <rcojocaru@xxxxxxxxxxxxxxx>
Acked-by: Wei Liu <wei.liu2@xxxxxxxxxx>
---
Changes since V6:
- Fixed monitor_enable_msr() (thanks to Kevin Tian).
- Added Wei Liu's ack.
---
tools/libxc/include/xenctrl.h | 9 ++-
tools/libxc/xc_monitor.c | 6 +-
xen/arch/x86/hvm/event.c | 3 +-
xen/arch/x86/hvm/hvm.c | 3 +-
xen/arch/x86/hvm/vmx/vmcs.c | 26 +-------
xen/arch/x86/hvm/vmx/vmx.c | 10 +--
xen/arch/x86/monitor.c | 125 +++++++++++++++++++++++++++++++++----
xen/arch/x86/vm_event.c | 3 +-
xen/common/vm_event.c | 5 ++
xen/include/asm-arm/monitor.h | 13 ++++
xen/include/asm-x86/domain.h | 4 +-
xen/include/asm-x86/hvm/hvm.h | 8 +--
xen/include/asm-x86/hvm/vmx/vmcs.h | 7 ---
xen/include/asm-x86/monitor.h | 12 ++++
xen/include/public/domctl.h | 5 +-
15 files changed, 170 insertions(+), 69 deletions(-)
diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index 42f201b..4fc5439 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -2153,8 +2153,13 @@ int xc_monitor_get_capabilities(xc_interface *xch,
domid_t domain_id,
int xc_monitor_write_ctrlreg(xc_interface *xch, domid_t domain_id,
uint16_t index, bool enable, bool sync,
bool onchangeonly);
-int xc_monitor_mov_to_msr(xc_interface *xch, domid_t domain_id, bool enable,
- bool extended_capture);
+/*
+ * A list of MSR indices can usually be found in /usr/include/asm/msr-index.h.
+ * Please consult the Intel/AMD manuals for more information on
+ * non-architectural indices.
+ */
+int xc_monitor_mov_to_msr(xc_interface *xch, domid_t domain_id, uint32_t msr,
+ bool enable);
int xc_monitor_singlestep(xc_interface *xch, domid_t domain_id, bool enable);
int xc_monitor_software_breakpoint(xc_interface *xch, domid_t domain_id,
bool enable);
diff --git a/tools/libxc/xc_monitor.c b/tools/libxc/xc_monitor.c
index b1705dd..78131b2 100644
--- a/tools/libxc/xc_monitor.c
+++ b/tools/libxc/xc_monitor.c
@@ -86,8 +86,8 @@ int xc_monitor_write_ctrlreg(xc_interface *xch, domid_t
domain_id,
return do_domctl(xch, &domctl);
}
-int xc_monitor_mov_to_msr(xc_interface *xch, domid_t domain_id, bool enable,
- bool extended_capture)
+int xc_monitor_mov_to_msr(xc_interface *xch, domid_t domain_id, uint32_t msr,
+ bool enable)
{
DECLARE_DOMCTL;
@@ -96,7 +96,7 @@ int xc_monitor_mov_to_msr(xc_interface *xch, domid_t
domain_id, bool enable,
domctl.u.monitor_op.op = enable ? XEN_DOMCTL_MONITOR_OP_ENABLE
: XEN_DOMCTL_MONITOR_OP_DISABLE;
domctl.u.monitor_op.event = XEN_DOMCTL_MONITOR_EVENT_MOV_TO_MSR;
- domctl.u.monitor_op.u.mov_to_msr.extended_capture = extended_capture;
+ domctl.u.monitor_op.u.mov_to_msr.msr = msr;
return do_domctl(xch, &domctl);
}
diff --git a/xen/arch/x86/hvm/event.c b/xen/arch/x86/hvm/event.c
index 56c5514..8fdb6f5 100644
--- a/xen/arch/x86/hvm/event.c
+++ b/xen/arch/x86/hvm/event.c
@@ -57,9 +57,8 @@ bool_t hvm_event_cr(unsigned int index, unsigned long value,
unsigned long old)
void hvm_event_msr(unsigned int msr, uint64_t value)
{
struct vcpu *curr = current;
- struct arch_domain *ad = &curr->domain->arch;
- if ( ad->monitor.mov_to_msr_enabled )
+ if ( monitored_msr(curr->domain, msr) )
{
vm_event_request_t req = {
.reason = VM_EVENT_REASON_MOV_TO_MSR,
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 82e2ed1..799fdeb 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -3694,7 +3694,6 @@ int hvm_msr_write_intercept(unsigned int msr, uint64_t
msr_content,
bool_t mtrr;
unsigned int edx, index;
int ret = X86EMUL_OKAY;
- struct arch_domain *currad = ¤t->domain->arch;
HVMTRACE_3D(MSR_WRITE, msr,
(uint32_t)msr_content, (uint32_t)(msr_content >> 32));
@@ -3702,7 +3701,7 @@ int hvm_msr_write_intercept(unsigned int msr, uint64_t
msr_content,
hvm_cpuid(1, NULL, NULL, NULL, &edx);
mtrr = !!(edx & cpufeat_mask(X86_FEATURE_MTRR));
- if ( may_defer && unlikely(currad->monitor.mov_to_msr_enabled) )
+ if ( may_defer && unlikely(monitored_msr(v->domain, msr)) )
{
ASSERT(v->arch.vm_event);
diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
index 8284281..f8421e8 100644
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -37,6 +37,7 @@
#include <asm/hvm/vmx/vvmx.h>
#include <asm/hvm/vmx/vmcs.h>
#include <asm/flushtlb.h>
+#include <asm/monitor.h>
#include <asm/shadow.h>
#include <asm/tboot.h>
#include <asm/apic.h>
@@ -108,18 +109,6 @@ u64 vmx_ept_vpid_cap __read_mostly;
u64 vmx_vmfunc __read_mostly;
bool_t vmx_virt_exception __read_mostly;
-const u32 vmx_introspection_force_enabled_msrs[] = {
- MSR_IA32_SYSENTER_EIP,
- MSR_IA32_SYSENTER_ESP,
- MSR_IA32_SYSENTER_CS,
- MSR_IA32_MC0_CTL,
- MSR_STAR,
- MSR_LSTAR
-};
-
-const unsigned int vmx_introspection_force_enabled_msrs_size =
- ARRAY_SIZE(vmx_introspection_force_enabled_msrs);
-
static DEFINE_PER_CPU_READ_MOSTLY(paddr_t, vmxon_region);
static DEFINE_PER_CPU(paddr_t, current_vmcs);
static DEFINE_PER_CPU(struct list_head, active_vmcs_list);
@@ -810,17 +799,8 @@ void vmx_disable_intercept_for_msr(struct vcpu *v, u32
msr, int type)
if ( msr_bitmap == NULL )
return;
- if ( unlikely(d->arch.monitor.mov_to_msr_enabled &&
- d->arch.monitor.mov_to_msr_extended) &&
- vm_event_check_ring(&d->vm_event->monitor) )
- {
- unsigned int i;
-
- /* Filter out MSR-s needed for memory introspection */
- for ( i = 0; i < vmx_introspection_force_enabled_msrs_size; i++ )
- if ( msr == vmx_introspection_force_enabled_msrs[i] )
- return;
- }
+ if ( unlikely(monitored_msr(d, msr)) )
+ return;
/*
* See Intel PRM Vol. 3, 20.6.9 (MSR-Bitmap Address). Early manuals
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index bc4410f..9135441 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -1958,16 +1958,12 @@ void vmx_hypervisor_cpuid_leaf(uint32_t sub_idx,
*eax |= XEN_HVM_CPUID_X2APIC_VIRT;
}
-static void vmx_enable_msr_exit_interception(struct domain *d)
+static void vmx_enable_msr_interception(struct domain *d, uint32_t msr)
{
struct vcpu *v;
- unsigned int i;
- /* Enable interception for MSRs needed for memory introspection. */
for_each_vcpu ( d, v )
- for ( i = 0; i < vmx_introspection_force_enabled_msrs_size; i++ )
- vmx_enable_intercept_for_msr(v,
vmx_introspection_force_enabled_msrs[i],
- MSR_TYPE_W);
+ vmx_enable_intercept_for_msr(v, msr, MSR_TYPE_W);
}
static bool_t vmx_is_singlestep_supported(void)
@@ -2166,7 +2162,7 @@ static struct hvm_function_table __initdata
vmx_function_table = {
.handle_eoi = vmx_handle_eoi,
.nhvm_hap_walk_L1_p2m = nvmx_hap_walk_L1_p2m,
.hypervisor_cpuid_leaf = vmx_hypervisor_cpuid_leaf,
- .enable_msr_exit_interception = vmx_enable_msr_exit_interception,
+ .enable_msr_interception = vmx_enable_msr_interception,
.is_singlestep_supported = vmx_is_singlestep_supported,
.set_mode = vmx_set_mode,
.altp2m_vcpu_update_p2m = vmx_vcpu_update_eptp,
diff --git a/xen/arch/x86/monitor.c b/xen/arch/x86/monitor.c
index 1fec412..ab6555f 100644
--- a/xen/arch/x86/monitor.c
+++ b/xen/arch/x86/monitor.c
@@ -22,6 +22,104 @@
#include <asm/monitor.h>
#include <public/vm_event.h>
+int arch_monitor_init_domain(struct domain *d)
+{
+ if ( !d->arch.monitor_msr_bitmap )
+ d->arch.monitor_msr_bitmap = xzalloc(struct monitor_msr_bitmap);
+
+ if ( !d->arch.monitor_msr_bitmap )
+ return -ENOMEM;
+
+ memset(&d->arch.monitor, 0, sizeof(d->arch.monitor));
+ memset(&d->monitor, 0, sizeof(d->monitor));
+
+ return 0;
+}
+
+void arch_monitor_cleanup_domain(struct domain *d)
+{
+ xfree(d->arch.monitor_msr_bitmap);
+ d->arch.monitor_msr_bitmap = NULL;
+}
+
+static void *monitor_bitmap_for_msr(struct domain *d, u32 *msr)
+{
+ ASSERT(d->arch.monitor_msr_bitmap && msr);
+
+ switch ( *msr )
+ {
+ case 0 ... 0x1fff:
+ BUILD_BUG_ON(ARRAY_SIZE(d->arch.monitor_msr_bitmap->low) * 8 < 0x1fff);
+ return &d->arch.monitor_msr_bitmap->low;
+
+ case 0x40000000 ... 0x40001fff:
+ BUILD_BUG_ON(
+ ARRAY_SIZE(d->arch.monitor_msr_bitmap->hypervisor) * 8 < 0x1fff);
+ *msr &= 0x1fff;
+ return &d->arch.monitor_msr_bitmap->hypervisor;
+
+ case 0xc0000000 ... 0xc0001fff:
+ BUILD_BUG_ON(ARRAY_SIZE(d->arch.monitor_msr_bitmap->high) * 8 <
0x1fff);
+ *msr &= 0x1fff;
+ return &d->arch.monitor_msr_bitmap->high;
+
+ default:
+ return NULL;
+ }
+}
+
+static int monitor_enable_msr(struct domain *d, u32 msr)
+{
+ u32 *bitmap;
+ u32 index = msr;
+
+ if ( !d->arch.monitor_msr_bitmap )
+ return -ENXIO;
+
+ bitmap = monitor_bitmap_for_msr(d, &index);
+
+ if ( !bitmap )
+ return -EINVAL;
+
+ __set_bit(index, bitmap);
+
+ hvm_enable_msr_interception(d, msr);
+
+ return 0;
+}
+
+static int monitor_disable_msr(struct domain *d, u32 msr)
+{
+ u32 *bitmap;
+
+ if ( !d->arch.monitor_msr_bitmap )
+ return -ENXIO;
+
+ bitmap = monitor_bitmap_for_msr(d, &msr);
+
+ if ( !bitmap )
+ return -EINVAL;
+
+ __clear_bit(msr, bitmap);
+
+ return 0;
+}
+
+bool_t monitored_msr(struct domain *d, u32 msr)
+{
+ u32 *bitmap;
+
+ if ( !d->arch.monitor_msr_bitmap )
+ return 0;
+
+ bitmap = monitor_bitmap_for_msr(d, &msr);
+
+ if ( !bitmap )
+ return 0;
+
+ return test_bit(msr, bitmap);
+}
+
int arch_monitor_domctl_event(struct domain *d,
struct xen_domctl_monitor_op *mop)
{
@@ -77,25 +175,28 @@ int arch_monitor_domctl_event(struct domain *d,
case XEN_DOMCTL_MONITOR_EVENT_MOV_TO_MSR:
{
- bool_t old_status = ad->monitor.mov_to_msr_enabled;
+ bool_t old_status;
+ int rc;
+ u32 msr = mop->u.mov_to_msr.msr;
- if ( unlikely(old_status == requested_status) )
- return -EEXIST;
+ domain_pause(d);
- if ( requested_status && mop->u.mov_to_msr.extended_capture &&
- !hvm_enable_msr_exit_interception(d) )
- return -EOPNOTSUPP;
+ old_status = monitored_msr(d, msr);
- domain_pause(d);
+ if ( unlikely(old_status == requested_status) )
+ {
+ domain_unpause(d);
+ return -EEXIST;
+ }
- if ( requested_status && mop->u.mov_to_msr.extended_capture )
- ad->monitor.mov_to_msr_extended = 1;
+ if ( requested_status )
+ rc = monitor_enable_msr(d, msr);
else
- ad->monitor.mov_to_msr_extended = 0;
+ rc = monitor_disable_msr(d, msr);
- ad->monitor.mov_to_msr_enabled = requested_status;
domain_unpause(d);
- break;
+
+ return rc;
}
case XEN_DOMCTL_MONITOR_EVENT_SINGLESTEP:
diff --git a/xen/arch/x86/vm_event.c b/xen/arch/x86/vm_event.c
index 5635603..a9d3861 100644
--- a/xen/arch/x86/vm_event.c
+++ b/xen/arch/x86/vm_event.c
@@ -20,6 +20,7 @@
#include <xen/sched.h>
#include <asm/hvm/hvm.h>
+#include <asm/monitor.h>
#include <asm/vm_event.h>
/* Implicitly serialized by the domctl lock. */
@@ -56,8 +57,6 @@ void vm_event_cleanup_domain(struct domain *d)
}
d->arch.mem_access_emulate_each_rep = 0;
- memset(&d->arch.monitor, 0, sizeof(d->arch.monitor));
- memset(&d->monitor, 0, sizeof(d->monitor));
}
void vm_event_toggle_singlestep(struct domain *d, struct vcpu *v)
diff --git a/xen/common/vm_event.c b/xen/common/vm_event.c
index 2906407..1ba12cb 100644
--- a/xen/common/vm_event.c
+++ b/xen/common/vm_event.c
@@ -27,6 +27,7 @@
#include <xen/mem_access.h>
#include <asm/p2m.h>
#include <asm/altp2m.h>
+#include <asm/monitor.h>
#include <asm/vm_event.h>
#include <xsm/xsm.h>
@@ -665,6 +666,9 @@ int vm_event_domctl(struct domain *d,
xen_domctl_vm_event_op_t *vec,
{
case XEN_VM_EVENT_ENABLE:
/* domain_pause() not required here, see XSA-99 */
+ rc = arch_monitor_init_domain(d);
+ if ( rc )
+ break;
rc = vm_event_enable(d, vec, ved, _VPF_mem_access,
HVM_PARAM_MONITOR_RING_PFN,
monitor_notification);
@@ -675,6 +679,7 @@ int vm_event_domctl(struct domain *d,
xen_domctl_vm_event_op_t *vec,
{
domain_pause(d);
rc = vm_event_disable(d, ved);
+ arch_monitor_cleanup_domain(d);
domain_unpause(d);
}
break;
diff --git a/xen/include/asm-arm/monitor.h b/xen/include/asm-arm/monitor.h
index 6e36e99..478f5e9 100644
--- a/xen/include/asm-arm/monitor.h
+++ b/xen/include/asm-arm/monitor.h
@@ -46,4 +46,17 @@ int arch_monitor_domctl_event(struct domain *d,
return -EOPNOTSUPP;
}
+static inline
+int arch_monitor_init_domain(struct domain *d)
+{
+ /* No arch-specific domain initialization on ARM. */
+ return 0;
+}
+
+static inline
+void arch_monitor_cleanup_domain(struct domain *d)
+{
+ /* No arch-specific domain cleanup on ARM. */
+}
+
#endif /* __ASM_ARM_MONITOR_H__ */
diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h
index 165e533..8a96242 100644
--- a/xen/include/asm-x86/domain.h
+++ b/xen/include/asm-x86/domain.h
@@ -401,12 +401,12 @@ struct arch_domain
unsigned int write_ctrlreg_enabled : 4;
unsigned int write_ctrlreg_sync : 4;
unsigned int write_ctrlreg_onchangeonly : 4;
- unsigned int mov_to_msr_enabled : 1;
- unsigned int mov_to_msr_extended : 1;
unsigned int singlestep_enabled : 1;
unsigned int software_breakpoint_enabled : 1;
} monitor;
+ struct monitor_msr_bitmap *monitor_msr_bitmap;
+
/* Mem_access emulation control */
bool_t mem_access_emulate_each_rep;
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index 7b7ff3f..9d1c0ef 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -211,7 +211,7 @@ struct hvm_function_table {
uint32_t *eax, uint32_t *ebx,
uint32_t *ecx, uint32_t *edx);
- void (*enable_msr_exit_interception)(struct domain *d);
+ void (*enable_msr_interception)(struct domain *d, uint32_t msr);
bool_t (*is_singlestep_supported)(void);
int (*set_mode)(struct vcpu *v, int mode);
@@ -565,11 +565,11 @@ static inline enum hvm_intblk
nhvm_interrupt_blocked(struct vcpu *v)
return hvm_funcs.nhvm_intr_blocked(v);
}
-static inline bool_t hvm_enable_msr_exit_interception(struct domain *d)
+static inline bool_t hvm_enable_msr_interception(struct domain *d, uint32_t
msr)
{
- if ( hvm_funcs.enable_msr_exit_interception )
+ if ( hvm_funcs.enable_msr_interception )
{
- hvm_funcs.enable_msr_exit_interception(d);
+ hvm_funcs.enable_msr_interception(d, msr);
return 1;
}
diff --git a/xen/include/asm-x86/hvm/vmx/vmcs.h
b/xen/include/asm-x86/hvm/vmx/vmcs.h
index b54f52f..7bf5326 100644
--- a/xen/include/asm-x86/hvm/vmx/vmcs.h
+++ b/xen/include/asm-x86/hvm/vmx/vmcs.h
@@ -562,13 +562,6 @@ enum vmcs_field {
HOST_RIP = 0x00006c16,
};
-/*
- * A set of MSR-s that need to be enabled for memory introspection
- * to work.
- */
-extern const u32 vmx_introspection_force_enabled_msrs[];
-extern const unsigned int vmx_introspection_force_enabled_msrs_size;
-
#define VMCS_VPID_WIDTH 16
#define MSR_TYPE_R 1
diff --git a/xen/include/asm-x86/monitor.h b/xen/include/asm-x86/monitor.h
index 0954b59..046f592 100644
--- a/xen/include/asm-x86/monitor.h
+++ b/xen/include/asm-x86/monitor.h
@@ -29,6 +29,12 @@
#define monitor_ctrlreg_bitmask(ctrlreg_index) (1U << (ctrlreg_index))
+struct monitor_msr_bitmap {
+ uint8_t low[1024];
+ uint8_t hypervisor[1024];
+ uint8_t high[1024];
+};
+
static inline
int arch_monitor_domctl_op(struct domain *d, struct xen_domctl_monitor_op *mop)
{
@@ -50,4 +56,10 @@ int arch_monitor_domctl_op(struct domain *d, struct
xen_domctl_monitor_op *mop)
int arch_monitor_domctl_event(struct domain *d,
struct xen_domctl_monitor_op *mop);
+int arch_monitor_init_domain(struct domain *d);
+
+void arch_monitor_cleanup_domain(struct domain *d);
+
+bool_t monitored_msr(struct domain *d, u32 msr);
+
#endif /* __ASM_X86_MONITOR_H__ */
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index 2457698..7be3924 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -37,7 +37,7 @@
#include "hvm/save.h"
#include "memory.h"
-#define XEN_DOMCTL_INTERFACE_VERSION 0x0000000b
+#define XEN_DOMCTL_INTERFACE_VERSION 0x0000000c
/*
* NB. xen_domctl.domain is an IN/OUT parameter for this operation.
@@ -1107,8 +1107,7 @@ struct xen_domctl_monitor_op {
} mov_to_cr;
struct {
- /* Enable the capture of an extended set of MSRs */
- uint8_t extended_capture;
+ uint32_t msr;
} mov_to_msr;
struct {
--
1.9.1
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