[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Xen-devel] [PATCH v4 13/17] x86/VPMU: Add privileged PMU mode
On 02/04/2014 06:31 AM, Jan Beulich wrote:
On 21.01.14 at 20:08, Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> wrote:
@@ -152,33 +162,62 @@ int vpmu_do_interrupt(struct cpu_user_regs *regs)
err = vpmu->arch_vpmu_ops->arch_vpmu_save(v);
vpmu_reset(vpmu, VPMU_CONTEXT_SAVE | VPMU_CONTEXT_LOADED);
- /* Store appropriate registers in xenpmu_data */
- if ( is_pv_32bit_domain(current->domain) )
+ if ( !is_hvm_domain(current->domain) )
{
- /*
- * 32-bit dom0 cannot process Xen's addresses (which are 64 bit)
- * and therefore we treat it the same way as a non-priviledged
- * PV 32-bit domain.
- */
- struct compat_cpu_user_regs *cmp;
-
- gregs = guest_cpu_user_regs();
-
- cmp = (struct compat_cpu_user_regs *)
- &v->arch.vpmu.xenpmu_data->pmu.r.regs;
- XLAT_cpu_user_regs(cmp, gregs);
+ uint16_t cs = (current->arch.flags & TF_kernel_mode) ? 0 : 0x3;
The surrounding if checks !hvm, i.e. both PV and PVH can make it
here. But TF_kernel_mode is meaningful for PV only.
As of this patch PVH doesn't work and you won't get into this code path.
And the later patch (#16) addresses this. (Although it unnecessary
calculates cs in the line above for PVH, only to call
hvm_get_segment_register() later. I'll move it to !pvh clause there).
+
+ /* Store appropriate registers in xenpmu_data */
+ if ( is_pv_32bit_domain(current->domain) )
+ {
+ gregs = guest_cpu_user_regs();
+
+ if ( (vpmu_mode & XENPMU_MODE_PRIV) &&
+ !is_pv_32bit_domain(v->domain) )
+ memcpy(&v->arch.vpmu.xenpmu_data->pmu.r.regs,
+ gregs, sizeof(struct cpu_user_regs));
+ else
+ {
+ /*
+ * 32-bit dom0 cannot process Xen's addresses (which are
+ * 64 bit) and therefore we treat it the same way as a
+ * non-priviledged PV 32-bit domain.
+ */
+
+ struct compat_cpu_user_regs *cmp;
+
+ cmp = (struct compat_cpu_user_regs *)
+ &v->arch.vpmu.xenpmu_data->pmu.r.regs;
+ XLAT_cpu_user_regs(cmp, gregs);
+ }
+ }
+ else if ( !is_control_domain(current->domain) &&
+ !is_idle_vcpu(current) )
+ {
+ /* PV guest */
+ gregs = guest_cpu_user_regs();
+ memcpy(&v->arch.vpmu.xenpmu_data->pmu.r.regs,
+ gregs, sizeof(struct cpu_user_regs));
+ }
+ else
+ memcpy(&v->arch.vpmu.xenpmu_data->pmu.r.regs,
+ regs, sizeof(struct cpu_user_regs));
+
+ gregs = &v->arch.vpmu.xenpmu_data->pmu.r.regs;
+ gregs->cs = cs;
And now you store a NUL selector (i.e. just the RPL bits) into the
output field?
}
- else if ( !is_control_domain(current->domain) &&
- !is_idle_vcpu(current) )
+ else
{
- /* PV guest */
+ /* HVM guest */
+ struct segment_register cs;
+
gregs = guest_cpu_user_regs();
memcpy(&v->arch.vpmu.xenpmu_data->pmu.r.regs,
gregs, sizeof(struct cpu_user_regs));
+
+ hvm_get_segment_register(current, x86_seg_cs, &cs);
+ gregs = &v->arch.vpmu.xenpmu_data->pmu.r.regs;
+ gregs->cs = cs.attr.fields.dpl;
And here too? If that's intended, a code comment is a must.
This is HVM-only path, PVH or PV don't go here so cs should be valid.
-boris
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel
|
