LinuxLists.cc - [PATCH] kvm/x86: add support for MONITOR_TRAP

2015-07-05 17:15:57

Subject: [PATCH] kvm/x86: add support for MONITOR_TRAP_FLAG

Allow a nested hypervisor to single step its guests.

Signed-off-by: Mihai Donțu <[email protected]>

---

This patch applies on top of current linux-next.
---
arch/x86/include/asm/vmx.h | 1 +
arch/x86/include/uapi/asm/vmx.h | 2 ++
arch/x86/kvm/vmx.c | 10 +++++++++-
3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index da772ed..9299ae5 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -47,6 +47,7 @@
#define CPU_BASED_MOV_DR_EXITING 0x00800000
#define CPU_BASED_UNCOND_IO_EXITING 0x01000000
#define CPU_BASED_USE_IO_BITMAPS 0x02000000
+#define CPU_BASED_MONITOR_TRAP_FLAG 0x08000000
#define CPU_BASED_USE_MSR_BITMAPS 0x10000000
#define CPU_BASED_MONITOR_EXITING 0x20000000
#define CPU_BASED_PAUSE_EXITING 0x40000000
diff --git a/arch/x86/include/uapi/asm/vmx.h b/arch/x86/include/uapi/asm/vmx.h
index 1fe9218..37fee27 100644
--- a/arch/x86/include/uapi/asm/vmx.h
+++ b/arch/x86/include/uapi/asm/vmx.h
@@ -58,6 +58,7 @@
#define EXIT_REASON_INVALID_STATE 33
#define EXIT_REASON_MSR_LOAD_FAIL 34
#define EXIT_REASON_MWAIT_INSTRUCTION 36
+#define EXIT_REASON_MONITOR_TRAP_FLAG 37
#define EXIT_REASON_MONITOR_INSTRUCTION 39
#define EXIT_REASON_PAUSE_INSTRUCTION 40
#define EXIT_REASON_MCE_DURING_VMENTRY 41
@@ -106,6 +107,7 @@
{ EXIT_REASON_MSR_READ, "MSR_READ" }, \
{ EXIT_REASON_MSR_WRITE, "MSR_WRITE" }, \
{ EXIT_REASON_MWAIT_INSTRUCTION, "MWAIT_INSTRUCTION" }, \
+ { EXIT_REASON_MONITOR_TRAP_FLAG, "MONITOR_TRAP_FLAG" }, \
{ EXIT_REASON_MONITOR_INSTRUCTION, "MONITOR_INSTRUCTION" }, \
{ EXIT_REASON_PAUSE_INSTRUCTION, "PAUSE_INSTRUCTION" }, \
{ EXIT_REASON_MCE_DURING_VMENTRY, "MCE_DURING_VMENTRY" }, \
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e856dd5..6d7c650 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2443,7 +2443,7 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx)
CPU_BASED_CR8_LOAD_EXITING | CPU_BASED_CR8_STORE_EXITING |
#endif
CPU_BASED_MOV_DR_EXITING | CPU_BASED_UNCOND_IO_EXITING |
- CPU_BASED_USE_IO_BITMAPS | CPU_BASED_MONITOR_EXITING |
+ CPU_BASED_USE_IO_BITMAPS | CPU_BASED_MONITOR_TRAP_FLAG | CPU_BASED_MONITOR_EXITING |
CPU_BASED_RDPMC_EXITING | CPU_BASED_RDTSC_EXITING |
CPU_BASED_PAUSE_EXITING | CPU_BASED_TPR_SHADOW |
CPU_BASED_ACTIVATE_SECONDARY_CONTROLS;
@@ -6246,6 +6246,11 @@ static int handle_mwait(struct kvm_vcpu *vcpu)
return handle_nop(vcpu);
}

+static int handle_monitor_trap(struct kvm_vcpu *vcpu)
+{
+ return 1;
+}
+
static int handle_monitor(struct kvm_vcpu *vcpu)
{
printk_once(KERN_WARNING "kvm: MONITOR instruction emulated as NOP!\n");
@@ -7282,6 +7287,7 @@ static int (*const kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
[EXIT_REASON_EPT_MISCONFIG] = handle_ept_misconfig,
[EXIT_REASON_PAUSE_INSTRUCTION] = handle_pause,
[EXIT_REASON_MWAIT_INSTRUCTION] = handle_mwait,
+ [EXIT_REASON_MONITOR_TRAP_FLAG] = handle_monitor_trap,
[EXIT_REASON_MONITOR_INSTRUCTION] = handle_monitor,
[EXIT_REASON_INVEPT] = handle_invept,
[EXIT_REASON_INVVPID] = handle_invvpid,
@@ -7542,6 +7548,8 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
return true;
case EXIT_REASON_MWAIT_INSTRUCTION:
return nested_cpu_has(vmcs12, CPU_BASED_MWAIT_EXITING);
+ case EXIT_REASON_MONITOR_TRAP_FLAG:
+ return nested_cpu_has(vmcs12, CPU_BASED_MONITOR_TRAP_FLAG);
case EXIT_REASON_MONITOR_INSTRUCTION:
return nested_cpu_has(vmcs12, CPU_BASED_MONITOR_EXITING);
case EXIT_REASON_PAUSE_INSTRUCTION:
--
2.4.5

2015-07-09 19:50:12

by Jan Kiszka

[permalink] [raw]

Subject: Re: [PATCH] kvm/x86: add support for MONITOR_TRAP_FLAG

On 2015-07-05 19:08, Mihai Donțu wrote:
> Allow a nested hypervisor to single step its guests.
>
> Signed-off-by: Mihai Donțu <[email protected]>
>
> ---
>
> This patch applies on top of current linux-next.
> ---
> arch/x86/include/asm/vmx.h | 1 +
> arch/x86/include/uapi/asm/vmx.h | 2 ++
> arch/x86/kvm/vmx.c | 10 +++++++++-
> 3 files changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
> index da772ed..9299ae5 100644
> --- a/arch/x86/include/asm/vmx.h
> +++ b/arch/x86/include/asm/vmx.h
> @@ -47,6 +47,7 @@
> #define CPU_BASED_MOV_DR_EXITING 0x00800000
> #define CPU_BASED_UNCOND_IO_EXITING 0x01000000
> #define CPU_BASED_USE_IO_BITMAPS 0x02000000
> +#define CPU_BASED_MONITOR_TRAP_FLAG 0x08000000
> #define CPU_BASED_USE_MSR_BITMAPS 0x10000000
> #define CPU_BASED_MONITOR_EXITING 0x20000000
> #define CPU_BASED_PAUSE_EXITING 0x40000000
> diff --git a/arch/x86/include/uapi/asm/vmx.h b/arch/x86/include/uapi/asm/vmx.h
> index 1fe9218..37fee27 100644
> --- a/arch/x86/include/uapi/asm/vmx.h
> +++ b/arch/x86/include/uapi/asm/vmx.h
> @@ -58,6 +58,7 @@
> #define EXIT_REASON_INVALID_STATE 33
> #define EXIT_REASON_MSR_LOAD_FAIL 34
> #define EXIT_REASON_MWAIT_INSTRUCTION 36
> +#define EXIT_REASON_MONITOR_TRAP_FLAG 37
> #define EXIT_REASON_MONITOR_INSTRUCTION 39
> #define EXIT_REASON_PAUSE_INSTRUCTION 40
> #define EXIT_REASON_MCE_DURING_VMENTRY 41
> @@ -106,6 +107,7 @@
> { EXIT_REASON_MSR_READ, "MSR_READ" }, \
> { EXIT_REASON_MSR_WRITE, "MSR_WRITE" }, \
> { EXIT_REASON_MWAIT_INSTRUCTION, "MWAIT_INSTRUCTION" }, \
> + { EXIT_REASON_MONITOR_TRAP_FLAG, "MONITOR_TRAP_FLAG" }, \
> { EXIT_REASON_MONITOR_INSTRUCTION, "MONITOR_INSTRUCTION" }, \
> { EXIT_REASON_PAUSE_INSTRUCTION, "PAUSE_INSTRUCTION" }, \
> { EXIT_REASON_MCE_DURING_VMENTRY, "MCE_DURING_VMENTRY" }, \
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index e856dd5..6d7c650 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -2443,7 +2443,7 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx)
> CPU_BASED_CR8_LOAD_EXITING | CPU_BASED_CR8_STORE_EXITING |
> #endif
> CPU_BASED_MOV_DR_EXITING | CPU_BASED_UNCOND_IO_EXITING |
> - CPU_BASED_USE_IO_BITMAPS | CPU_BASED_MONITOR_EXITING |
> + CPU_BASED_USE_IO_BITMAPS | CPU_BASED_MONITOR_TRAP_FLAG | CPU_BASED_MONITOR_EXITING |

Overlong line.

> CPU_BASED_RDPMC_EXITING | CPU_BASED_RDTSC_EXITING |
> CPU_BASED_PAUSE_EXITING | CPU_BASED_TPR_SHADOW |
> CPU_BASED_ACTIVATE_SECONDARY_CONTROLS;
> @@ -6246,6 +6246,11 @@ static int handle_mwait(struct kvm_vcpu *vcpu)
> return handle_nop(vcpu);
> }
>
> +static int handle_monitor_trap(struct kvm_vcpu *vcpu)
> +{
> + return 1;
> +}
> +
> static int handle_monitor(struct kvm_vcpu *vcpu)
> {
> printk_once(KERN_WARNING "kvm: MONITOR instruction emulated as NOP!\n");
> @@ -7282,6 +7287,7 @@ static int (*const kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
> [EXIT_REASON_EPT_MISCONFIG] = handle_ept_misconfig,
> [EXIT_REASON_PAUSE_INSTRUCTION] = handle_pause,
> [EXIT_REASON_MWAIT_INSTRUCTION] = handle_mwait,
> + [EXIT_REASON_MONITOR_TRAP_FLAG] = handle_monitor_trap,
> [EXIT_REASON_MONITOR_INSTRUCTION] = handle_monitor,
> [EXIT_REASON_INVEPT] = handle_invept,
> [EXIT_REASON_INVVPID] = handle_invvpid,
> @@ -7542,6 +7548,8 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
> return true;
> case EXIT_REASON_MWAIT_INSTRUCTION:
> return nested_cpu_has(vmcs12, CPU_BASED_MWAIT_EXITING);
> + case EXIT_REASON_MONITOR_TRAP_FLAG:
> + return nested_cpu_has(vmcs12, CPU_BASED_MONITOR_TRAP_FLAG);
> case EXIT_REASON_MONITOR_INSTRUCTION:
> return nested_cpu_has(vmcs12, CPU_BASED_MONITOR_EXITING);
> case EXIT_REASON_PAUSE_INSTRUCTION:
>

Looks OK otherwise. If you fix up the style thing, you may add my

Reviewed-by: Jan Kiszka <[email protected]>

Jan

--
Siemens AG, Corporate Technology, CT RTC ITP SES-DE
Corporate Competence Center Embedded Linux

2015-07-10 11:28:42

by Paolo Bonzini

[permalink] [raw]

Subject: Re: [PATCH] kvm/x86: add support for MONITOR_TRAP_FLAG

2015-07-10 16:05:47

by Mihai Donțu

[permalink] [raw]

Subject: Re: [PATCH] kvm/x86: add support for MONITOR_TRAP_FLAG

On Friday 10 July 2015 13:28:26 Paolo Bonzini wrote:
> On 09/07/2015 21:49, Jan Kiszka wrote:
> >> > CPU_BASED_MOV_DR_EXITING | CPU_BASED_UNCOND_IO_EXITING |
> >> > - CPU_BASED_USE_IO_BITMAPS | CPU_BASED_MONITOR_EXITING |
> >> > + CPU_BASED_USE_IO_BITMAPS | CPU_BASED_MONITOR_TRAP_FLAG | CPU_BASED_MONITOR_EXITING |
> > Overlong line.
>
> Fixed and applied.

Thank you!

--
Mihai Donțu