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[Xen-devel] [PATCH v1] x86/hvm: Add MSR old value

From: Alexandru Isaila <aisaila@xxxxxxxxxxxxxxx>

Date: Thu, 12 Oct 2017 12:10:25 +0300

Cc: sstabellini@xxxxxxxxxx, wei.liu2@xxxxxxxxxx, rcojocaru@xxxxxxxxxxxxxxx, konrad.wilk@xxxxxxxxxx, George.Dunlap@xxxxxxxxxxxxx, andrew.cooper3@xxxxxxxxxx, ian.jackson@xxxxxxxxxxxxx, tim@xxxxxxx, tamas@xxxxxxxxxxxxx, jbeulich@xxxxxxxx, Alexandru Isaila <aisaila@xxxxxxxxxxxxxxx>

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This patch adds the old value param and the onchangeonly option to the VM_EVENT_REASON_MOV_TO_MSR event. The param was added to the vm_event_mov_to_msr struct and to the hvm_monitor_msr function. Finally I've changed the bool_t param to a bool for the hvm_msr_write_intercept function. Signed-off-by: Alexandru Isaila <aisaila@xxxxxxxxxxxxxxx> --- tools/libxc/include/xenctrl.h | 2 +- tools/libxc/xc_monitor.c | 3 ++- xen/arch/x86/hvm/hvm.c | 10 ++++++++-- xen/arch/x86/hvm/monitor.c | 9 ++++++--- xen/arch/x86/monitor.c | 26 +++++++++++++++++++++++--- xen/include/asm-x86/hvm/monitor.h | 2 +- xen/include/asm-x86/hvm/support.h | 2 +- xen/include/asm-x86/monitor.h | 2 ++ xen/include/public/domctl.h | 2 ++ xen/include/public/vm_event.h | 5 +++-- 10 files changed, 49 insertions(+), 14 deletions(-) diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h index 3bcab3c..b99d6eb 100644 --- a/tools/libxc/include/xenctrl.h +++ b/tools/libxc/include/xenctrl.h @@ -2048,7 +2048,7 @@ int xc_monitor_write_ctrlreg(xc_interface *xch, domid_t domain_id, * non-architectural indices. */ int xc_monitor_mov_to_msr(xc_interface *xch, domid_t domain_id, uint32_t msr, - bool enable); + bool enable, bool onchangeonly); 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 6046680..09d04be 100644 --- a/tools/libxc/xc_monitor.c +++ b/tools/libxc/xc_monitor.c @@ -90,7 +90,7 @@ int xc_monitor_write_ctrlreg(xc_interface *xch, domid_t domain_id, } int xc_monitor_mov_to_msr(xc_interface *xch, domid_t domain_id, uint32_t msr, - bool enable) + bool enable, bool onchangeonly) { DECLARE_DOMCTL; @@ -100,6 +100,7 @@ int xc_monitor_mov_to_msr(xc_interface *xch, domid_t domain_id, uint32_t msr, : 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.msr = msr; + domctl.u.monitor_op.u.mov_to_msr.onchangeonly = onchangeonly; return do_domctl(xch, &domctl); } diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index 205b4cb..0238787 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -3489,7 +3489,7 @@ int hvm_msr_read_intercept(unsigned int msr, uint64_t *msr_content) } int hvm_msr_write_intercept(unsigned int msr, uint64_t msr_content, - bool_t may_defer) + bool may_defer) { struct vcpu *v = current; struct domain *d = v->domain; @@ -3500,6 +3500,12 @@ int hvm_msr_write_intercept(unsigned int msr, uint64_t msr_content, if ( may_defer && unlikely(monitored_msr(v->domain, msr)) ) { + uint64_t msr_old_content; + + ret = hvm_msr_read_intercept(msr, &msr_old_content); + if ( ret != X86EMUL_OKAY ) + return ret; + ASSERT(v->arch.vm_event); /* The actual write will occur in hvm_do_resume() (if permitted). */ @@ -3507,7 +3513,7 @@ int hvm_msr_write_intercept(unsigned int msr, uint64_t msr_content, v->arch.vm_event->write_data.msr = msr; v->arch.vm_event->write_data.value = msr_content; - hvm_monitor_msr(msr, msr_content); + hvm_monitor_msr(msr, msr_content, msr_old_content); return X86EMUL_OKAY; } diff --git a/xen/arch/x86/hvm/monitor.c b/xen/arch/x86/hvm/monitor.c index 4ce778c..74f83b4 100644 --- a/xen/arch/x86/hvm/monitor.c +++ b/xen/arch/x86/hvm/monitor.c @@ -74,16 +74,19 @@ bool hvm_monitor_emul_unimplemented(void) monitor_traps(curr, true, &req) == 1; } -void hvm_monitor_msr(unsigned int msr, uint64_t value) +void hvm_monitor_msr(unsigned int msr, uint64_t new_value, uint64_t old_value) { struct vcpu *curr = current; - if ( monitored_msr(curr->domain, msr) ) + if ( monitored_msr(curr->domain, msr) && + ( !monitored_msr_onchangeonly(curr->domain, msr) || + new_value != old_value ) ) { vm_event_request_t req = { .reason = VM_EVENT_REASON_MOV_TO_MSR, .u.mov_to_msr.msr = msr, - .u.mov_to_msr.value = value, + .u.mov_to_msr.new_value = new_value, + .u.mov_to_msr.old_value = old_value }; monitor_traps(curr, 1, &req); diff --git a/xen/arch/x86/monitor.c b/xen/arch/x86/monitor.c index e59f1f5..a3046c6 100644 --- a/xen/arch/x86/monitor.c +++ b/xen/arch/x86/monitor.c @@ -25,7 +25,7 @@ int arch_monitor_init_domain(struct domain *d) { if ( !d->arch.monitor.msr_bitmap ) - d->arch.monitor.msr_bitmap = xzalloc(struct monitor_msr_bitmap); + d->arch.monitor.msr_bitmap = xzalloc_array(struct monitor_msr_bitmap, 2); if ( !d->arch.monitor.msr_bitmap ) return -ENOMEM; @@ -67,7 +67,7 @@ static unsigned long *monitor_bitmap_for_msr(const struct domain *d, u32 *msr) } } -static int monitor_enable_msr(struct domain *d, u32 msr) +static int monitor_enable_msr(struct domain *d, u32 msr, bool onchangeonly) { unsigned long *bitmap; u32 index = msr; @@ -84,6 +84,11 @@ static int monitor_enable_msr(struct domain *d, u32 msr) hvm_enable_msr_interception(d, msr); + if( onchangeonly ) + __set_bit(index + sizeof(struct monitor_msr_bitmap), bitmap); + else + __clear_bit(index + sizeof(struct monitor_msr_bitmap), bitmap); + return 0; } @@ -119,6 +124,21 @@ bool monitored_msr(const struct domain *d, u32 msr) return test_bit(msr, bitmap); } +bool monitored_msr_onchangeonly(const struct domain *d, u32 msr) +{ + const unsigned long *bitmap; + + if ( !d->arch.monitor.msr_bitmap ) + return false; + + bitmap = monitor_bitmap_for_msr(d, &msr); + + if ( !bitmap ) + return false; + + return test_bit(msr + sizeof(struct monitor_msr_bitmap), bitmap); +} + int arch_monitor_domctl_event(struct domain *d, struct xen_domctl_monitor_op *mop) { @@ -198,7 +218,7 @@ int arch_monitor_domctl_event(struct domain *d, } if ( requested_status ) - rc = monitor_enable_msr(d, msr); + rc = monitor_enable_msr(d, msr, mop->u.mov_to_msr.onchangeonly); else rc = monitor_disable_msr(d, msr); diff --git a/xen/include/asm-x86/hvm/monitor.h b/xen/include/asm-x86/hvm/monitor.h index 6e22091..260d7b0 100644 --- a/xen/include/asm-x86/hvm/monitor.h +++ b/xen/include/asm-x86/hvm/monitor.h @@ -37,7 +37,7 @@ bool hvm_monitor_cr(unsigned int index, unsigned long value, unsigned long old); #define hvm_monitor_crX(cr, new, old) \ hvm_monitor_cr(VM_EVENT_X86_##cr, new, old) -void hvm_monitor_msr(unsigned int msr, uint64_t value); +void hvm_monitor_msr(unsigned int msr, uint64_t new_value, uint64_t old_value); void hvm_monitor_descriptor_access(uint64_t exit_info, uint64_t vmx_exit_qualification, uint8_t descriptor, bool is_write); diff --git a/xen/include/asm-x86/hvm/support.h b/xen/include/asm-x86/hvm/support.h index d784fc1..ac33eea 100644 --- a/xen/include/asm-x86/hvm/support.h +++ b/xen/include/asm-x86/hvm/support.h @@ -154,7 +154,7 @@ void hvm_ud_intercept(struct cpu_user_regs *); int __must_check hvm_msr_read_intercept( unsigned int msr, uint64_t *msr_content); int __must_check hvm_msr_write_intercept( - unsigned int msr, uint64_t msr_content, bool_t may_defer); + unsigned int msr, uint64_t msr_content, bool may_defer); #endif /* __ASM_X86_HVM_SUPPORT_H__ */ diff --git a/xen/include/asm-x86/monitor.h b/xen/include/asm-x86/monitor.h index 0ada970..575b3c6 100644 --- a/xen/include/asm-x86/monitor.h +++ b/xen/include/asm-x86/monitor.h @@ -105,4 +105,6 @@ void arch_monitor_cleanup_domain(struct domain *d); bool monitored_msr(const struct domain *d, u32 msr); +bool monitored_msr_onchangeonly(const 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 8853445..3dfadae 100644 --- a/xen/include/public/domctl.h +++ b/xen/include/public/domctl.h @@ -1046,6 +1046,8 @@ struct xen_domctl_monitor_op { struct { uint32_t msr; + /* Send event only on a change of value */ + uint8_t onchangeonly; } mov_to_msr; struct { diff --git a/xen/include/public/vm_event.h b/xen/include/public/vm_event.h index b531f71..36e3f46 100644 --- a/xen/include/public/vm_event.h +++ b/xen/include/public/vm_event.h @@ -29,7 +29,7 @@ #include "xen.h" -#define VM_EVENT_INTERFACE_VERSION 0x00000002 +#define VM_EVENT_INTERFACE_VERSION 0x00000003 #if defined(__XEN__) || defined(__XEN_TOOLS__) @@ -260,7 +260,8 @@ struct vm_event_debug { struct vm_event_mov_to_msr { uint64_t msr; - uint64_t value; + uint64_t new_value; + uint64_t old_value; }; #define VM_EVENT_DESC_IDTR 1 -- 2.7.4 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel

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