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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen stable-4.6] x86/vmx: Support remote access to the MSR lists
commit 7d98594e6eceb2b63a773259f9f1cce10b197eb8
Author: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Mon May 7 11:57:00 2018 +0100
Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Tue Aug 14 17:39:56 2018 +0100
x86/vmx: Support remote access to the MSR lists
At the moment, all modifications of the MSR lists are in current context.
However, future changes may need to put MSR_EFER into the lists from domctl
hypercall context.
Plumb a struct vcpu parameter down through the infrastructure, and use
vmx_vmcs_{enter,exit}() for safe access to the VMCS in vmx_add_msr(). Use
assertions to ensure that access is either in current context, or while the
vcpu is paused.
Note these expectations beside the fields in arch_vmx_struct, and reorder
the
fields to avoid unnecessary padding.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Acked-by: Kevin Tian <kevin.tian@xxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
(cherry picked from commit 80599f0b770199116aa753bfdfac9bfe2e8ea86a)
---
xen/arch/x86/cpu/vpmu_intel.c | 14 ++++++-------
xen/arch/x86/hvm/vmx/vmcs.c | 40 ++++++++++++++++++++++++++++----------
xen/arch/x86/hvm/vmx/vmx.c | 10 ++++++----
xen/include/asm-x86/atomic.h | 2 +-
xen/include/asm-x86/hvm/vmx/vmcs.h | 34 ++++++++++++++++++++------------
xen/include/xen/sched.h | 2 +-
6 files changed, 67 insertions(+), 35 deletions(-)
diff --git a/xen/arch/x86/cpu/vpmu_intel.c b/xen/arch/x86/cpu/vpmu_intel.c
index 24fa793219..c880123a27 100644
--- a/xen/arch/x86/cpu/vpmu_intel.c
+++ b/xen/arch/x86/cpu/vpmu_intel.c
@@ -480,12 +480,12 @@ static int core2_vpmu_alloc_resource(struct vcpu *v)
if ( has_hvm_container_vcpu(v) )
{
wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0);
- if ( vmx_add_host_load_msr(MSR_CORE_PERF_GLOBAL_CTRL) )
+ if ( vmx_add_host_load_msr(v, MSR_CORE_PERF_GLOBAL_CTRL) )
goto out_err;
- if ( vmx_add_guest_msr(MSR_CORE_PERF_GLOBAL_CTRL) )
+ if ( vmx_add_guest_msr(v, MSR_CORE_PERF_GLOBAL_CTRL) )
goto out_err;
- vmx_write_guest_msr(MSR_CORE_PERF_GLOBAL_CTRL, 0);
+ vmx_write_guest_msr(v, MSR_CORE_PERF_GLOBAL_CTRL, 0);
}
core2_vpmu_cxt = xzalloc_bytes(sizeof(*core2_vpmu_cxt) +
@@ -632,7 +632,7 @@ static int core2_vpmu_do_wrmsr(unsigned int msr, uint64_t
msr_content,
return -EINVAL;
if ( has_hvm_container_vcpu(v) )
- vmx_read_guest_msr(MSR_CORE_PERF_GLOBAL_CTRL,
+ vmx_read_guest_msr(v, MSR_CORE_PERF_GLOBAL_CTRL,
&core2_vpmu_cxt->global_ctrl);
else
rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, core2_vpmu_cxt->global_ctrl);
@@ -661,7 +661,7 @@ static int core2_vpmu_do_wrmsr(unsigned int msr, uint64_t
msr_content,
return -EINVAL;
if ( has_hvm_container_vcpu(v) )
- vmx_read_guest_msr(MSR_CORE_PERF_GLOBAL_CTRL,
+ vmx_read_guest_msr(v, MSR_CORE_PERF_GLOBAL_CTRL,
&core2_vpmu_cxt->global_ctrl);
else
rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, core2_vpmu_cxt->global_ctrl);
@@ -680,7 +680,7 @@ static int core2_vpmu_do_wrmsr(unsigned int msr, uint64_t
msr_content,
else
{
if ( has_hvm_container_vcpu(v) )
- vmx_write_guest_msr(MSR_CORE_PERF_GLOBAL_CTRL, msr_content);
+ vmx_write_guest_msr(v, MSR_CORE_PERF_GLOBAL_CTRL, msr_content);
else
wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, msr_content);
}
@@ -714,7 +714,7 @@ static int core2_vpmu_do_rdmsr(unsigned int msr, uint64_t
*msr_content)
break;
case MSR_CORE_PERF_GLOBAL_CTRL:
if ( has_hvm_container_vcpu(v) )
- vmx_read_guest_msr(MSR_CORE_PERF_GLOBAL_CTRL, msr_content);
+ vmx_read_guest_msr(v, MSR_CORE_PERF_GLOBAL_CTRL, msr_content);
else
rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, *msr_content);
break;
diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
index be5abf8a52..327bc30a85 100644
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -1312,13 +1312,15 @@ static struct vmx_msr_entry *locate_msr_entry(
return start;
}
-struct vmx_msr_entry *vmx_find_msr(uint32_t msr, enum vmx_msr_list_type type)
+struct vmx_msr_entry *vmx_find_msr(const struct vcpu *v, uint32_t msr,
+ enum vmx_msr_list_type type)
{
- struct vcpu *curr = current;
- struct arch_vmx_struct *vmx = &curr->arch.hvm_vmx;
+ const struct arch_vmx_struct *vmx = &v->arch.hvm_vmx;
struct vmx_msr_entry *start = NULL, *ent, *end;
unsigned int total;
+ ASSERT(v == current || !vcpu_runnable(v));
+
switch ( type )
{
case VMX_MSR_HOST:
@@ -1344,12 +1346,14 @@ struct vmx_msr_entry *vmx_find_msr(uint32_t msr, enum
vmx_msr_list_type type)
return ((ent < end) && (ent->index == msr)) ? ent : NULL;
}
-int vmx_add_msr(uint32_t msr, enum vmx_msr_list_type type)
+int vmx_add_msr(struct vcpu *v, uint32_t msr, enum vmx_msr_list_type type)
{
- struct vcpu *curr = current;
- struct arch_vmx_struct *vmx = &curr->arch.hvm_vmx;
+ struct arch_vmx_struct *vmx = &v->arch.hvm_vmx;
struct vmx_msr_entry **ptr, *start = NULL, *ent, *end;
unsigned int total;
+ int rc;
+
+ ASSERT(v == current || !vcpu_runnable(v));
switch ( type )
{
@@ -1368,13 +1372,18 @@ int vmx_add_msr(uint32_t msr, enum vmx_msr_list_type
type)
return -EINVAL;
}
+ vmx_vmcs_enter(v);
+
/* Allocate memory on first use. */
if ( unlikely(!*ptr) )
{
paddr_t addr;
if ( (*ptr = alloc_xenheap_page()) == NULL )
- return -ENOMEM;
+ {
+ rc = -ENOMEM;
+ goto out;
+ }
addr = virt_to_maddr(*ptr);
@@ -1396,10 +1405,16 @@ int vmx_add_msr(uint32_t msr, enum vmx_msr_list_type
type)
ent = locate_msr_entry(start, end, msr);
if ( (ent < end) && (ent->index == msr) )
- return 0;
+ {
+ rc = 0;
+ goto out;
+ }
if ( total == (PAGE_SIZE / sizeof(*ent)) )
- return -ENOSPC;
+ {
+ rc = -ENOSPC;
+ goto out;
+ }
memmove(ent + 1, ent, sizeof(*ent) * (end - ent));
@@ -1420,7 +1435,12 @@ int vmx_add_msr(uint32_t msr, enum vmx_msr_list_type
type)
break;
}
- return 0;
+ rc = 0;
+
+ out:
+ vmx_vmcs_exit(v);
+
+ return rc;
}
void vmx_set_eoi_exit_bitmap(struct vcpu *v, u8 vector)
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index 1306d35f7d..38239dbe46 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -2367,6 +2367,8 @@ static int is_last_branch_msr(u32 ecx)
static int vmx_msr_read_intercept(unsigned int msr, uint64_t *msr_content)
{
+ struct vcpu *curr = current;
+
HVM_DBG_LOG(DBG_LEVEL_MSR, "ecx=%#x", msr);
switch ( msr )
@@ -2429,7 +2431,7 @@ static int vmx_msr_read_intercept(unsigned int msr,
uint64_t *msr_content)
goto done;
}
- if ( vmx_read_guest_msr(msr, msr_content) == 0 )
+ if ( vmx_read_guest_msr(curr, msr, msr_content) == 0 )
break;
if ( is_last_branch_msr(msr) )
@@ -2603,12 +2605,12 @@ static int vmx_msr_write_intercept(unsigned int msr,
uint64_t msr_content)
for ( ; (rc == 0) && lbr->count; lbr++ )
for ( i = 0; (rc == 0) && (i < lbr->count); i++ )
- if ( (rc = vmx_add_guest_msr(lbr->base + i)) == 0 )
+ if ( (rc = vmx_add_guest_msr(v, lbr->base + i)) == 0 )
vmx_disable_intercept_for_msr(v, lbr->base + i,
MSR_TYPE_R | MSR_TYPE_W);
}
if ( (rc < 0) ||
- (msr_content && (vmx_add_host_load_msr(msr) < 0)) )
+ (msr_content && (vmx_add_host_load_msr(v, msr) < 0)) )
hvm_inject_hw_exception(TRAP_machine_check,
HVM_DELIVER_NO_ERROR_CODE);
else
__vmwrite(GUEST_IA32_DEBUGCTL, msr_content);
@@ -2650,7 +2652,7 @@ static int vmx_msr_write_intercept(unsigned int msr,
uint64_t msr_content)
switch ( long_mode_do_msr_write(msr, msr_content) )
{
case HNDL_unhandled:
- if ( (vmx_write_guest_msr(msr, msr_content) != 0) &&
+ if ( (vmx_write_guest_msr(v, msr, msr_content) != 0) &&
!is_last_branch_msr(msr) )
switch ( wrmsr_hypervisor_regs(msr, msr_content) )
{
diff --git a/xen/include/asm-x86/atomic.h b/xen/include/asm-x86/atomic.h
index 2b8c8773ca..3adf0407a6 100644
--- a/xen/include/asm-x86/atomic.h
+++ b/xen/include/asm-x86/atomic.h
@@ -94,7 +94,7 @@ typedef struct { int counter; } atomic_t;
*
* Atomically reads the value of @v.
*/
-static inline int atomic_read(atomic_t *v)
+static inline int atomic_read(const atomic_t *v)
{
return read_atomic(&v->counter);
}
diff --git a/xen/include/asm-x86/hvm/vmx/vmcs.h
b/xen/include/asm-x86/hvm/vmx/vmcs.h
index 1dab1f87a4..b12bc1efc6 100644
--- a/xen/include/asm-x86/hvm/vmx/vmcs.h
+++ b/xen/include/asm-x86/hvm/vmx/vmcs.h
@@ -119,10 +119,17 @@ struct arch_vmx_struct {
unsigned long cstar;
unsigned long *msr_bitmap;
- unsigned int msr_count;
+
+ /*
+ * Most accesses to the MSR host/guest load/save lists are in current
+ * context. However, the data can be modified by toolstack/migration
+ * actions. Remote access is only permitted for paused vcpus, and is
+ * protected under the domctl lock.
+ */
struct vmx_msr_entry *msr_area;
- unsigned int host_msr_count;
struct vmx_msr_entry *host_msr_area;
+ unsigned int msr_count;
+ unsigned int host_msr_count;
unsigned long eoi_exitmap_changed;
DECLARE_BITMAP(eoi_exit_bitmap, NR_VECTORS);
@@ -495,23 +502,25 @@ enum vmx_msr_list_type {
VMX_MSR_GUEST, /* MSRs saved on VMExit, loaded on VMEntry. */
};
-int vmx_add_msr(uint32_t msr, enum vmx_msr_list_type type);
+int vmx_add_msr(struct vcpu *v, uint32_t msr, enum vmx_msr_list_type type);
-static inline int vmx_add_host_load_msr(uint32_t msr)
+static inline int vmx_add_guest_msr(struct vcpu *v, uint32_t msr)
{
- return vmx_add_msr(msr, VMX_MSR_HOST);
+ return vmx_add_msr(v, msr, VMX_MSR_GUEST);
}
-static inline int vmx_add_guest_msr(uint32_t msr)
+static inline int vmx_add_host_load_msr(struct vcpu *v, uint32_t msr)
{
- return vmx_add_msr(msr, VMX_MSR_GUEST);
+ return vmx_add_msr(v, msr, VMX_MSR_HOST);
}
-struct vmx_msr_entry *vmx_find_msr(uint32_t msr, enum vmx_msr_list_type type);
+struct vmx_msr_entry *vmx_find_msr(const struct vcpu *v, uint32_t msr,
+ enum vmx_msr_list_type type);
-static inline int vmx_read_guest_msr(uint32_t msr, uint64_t *val)
+static inline int vmx_read_guest_msr(const struct vcpu *v, uint32_t msr,
+ uint64_t *val)
{
- const struct vmx_msr_entry *ent = vmx_find_msr(msr, VMX_MSR_GUEST);
+ const struct vmx_msr_entry *ent = vmx_find_msr(v, msr, VMX_MSR_GUEST);
if ( !ent )
return -ESRCH;
@@ -521,9 +530,10 @@ static inline int vmx_read_guest_msr(uint32_t msr,
uint64_t *val)
return 0;
}
-static inline int vmx_write_guest_msr(uint32_t msr, uint64_t val)
+static inline int vmx_write_guest_msr(struct vcpu *v, uint32_t msr,
+ uint64_t val)
{
- struct vmx_msr_entry *ent = vmx_find_msr(msr, VMX_MSR_GUEST);
+ struct vmx_msr_entry *ent = vmx_find_msr(v, msr, VMX_MSR_GUEST);
if ( !ent )
return -ESRCH;
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 21a6e4915d..d1902f396b 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -779,7 +779,7 @@ static inline struct domain *next_domain_in_cpupool(
#define _VPF_in_reset 7
#define VPF_in_reset (1UL<<_VPF_in_reset)
-static inline int vcpu_runnable(struct vcpu *v)
+static inline int vcpu_runnable(const struct vcpu *v)
{
return !(v->pause_flags |
atomic_read(&v->pause_count) |
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.6
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