Check if Intel Processor Trace feature is supported by current
processor. Define hvm_ipt_supported function.
Signed-off-by: Michal Leszczynski <michal.leszczynski@cert.pl>
---
xen/arch/x86/hvm/vmx/vmx.c | 24 +++++++++++++++++++++
xen/include/asm-x86/cpufeature.h | 1 +
xen/include/asm-x86/hvm/hvm.h | 9 ++++++++
xen/include/asm-x86/hvm/vmx/vmcs.h | 1 +
xen/include/public/arch-x86/cpufeatureset.h | 1 +
5 files changed, 36 insertions(+)
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index ab19d9424e..a91bbdb798 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -2484,6 +2484,7 @@ static bool __init has_if_pschange_mc(void)
const struct hvm_function_table * __init start_vmx(void)
{
+ u64 _vmx_misc_cap;
set_in_cr4(X86_CR4_VMXE);
if ( vmx_vmcs_init() )
@@ -2557,6 +2558,29 @@ const struct hvm_function_table * __init start_vmx(void)
vmx_function_table.get_guest_bndcfgs = vmx_get_guest_bndcfgs;
}
+ /* Check whether IPT is supported in VMX operation */
+ vmx_function_table.ipt_supported = 1;
+
+ if ( !cpu_has_ipt )
+ {
+ vmx_function_table.ipt_supported = 0;
+ printk("VMX: Missing support for Intel Processor Trace x86 feature.\n");
+ }
+
+ rdmsrl(MSR_IA32_VMX_MISC, _vmx_misc_cap);
+
+ if ( !( _vmx_misc_cap & VMX_MISC_PT_SUPPORTED ) )
+ {
+ vmx_function_table.ipt_supported = 0;
+ printk("VMX: Missing support for Intel Processor Trace in VMX operation, VMX_MISC caps: %llx\n",
+ (unsigned long long)_vmx_misc_cap);
+ }
+
+ if (vmx_function_table.ipt_supported)
+ {
+ printk("VMX: Intel Processor Trace is SUPPORTED");
+ }
+
lbr_tsx_fixup_check();
ler_to_fixup_check();
diff --git a/xen/include/asm-x86/cpufeature.h b/xen/include/asm-x86/cpufeature.h
index f790d5c1f8..8d7955dd87 100644
--- a/xen/include/asm-x86/cpufeature.h
+++ b/xen/include/asm-x86/cpufeature.h
@@ -104,6 +104,7 @@
#define cpu_has_clwb boot_cpu_has(X86_FEATURE_CLWB)
#define cpu_has_avx512er boot_cpu_has(X86_FEATURE_AVX512ER)
#define cpu_has_avx512cd boot_cpu_has(X86_FEATURE_AVX512CD)
+#define cpu_has_ipt boot_cpu_has(X86_FEATURE_IPT)
#define cpu_has_sha boot_cpu_has(X86_FEATURE_SHA)
#define cpu_has_avx512bw boot_cpu_has(X86_FEATURE_AVX512BW)
#define cpu_has_avx512vl boot_cpu_has(X86_FEATURE_AVX512VL)
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index 1eb377dd82..48465b6067 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -96,6 +96,9 @@ struct hvm_function_table {
/* Necessary hardware support for alternate p2m's? */
bool altp2m_supported;
+ /* Hardware support for IPT? */
+ bool ipt_supported;
+
/* Hardware virtual interrupt delivery enable? */
bool virtual_intr_delivery_enabled;
@@ -630,6 +633,12 @@ static inline bool hvm_altp2m_supported(void)
return hvm_funcs.altp2m_supported;
}
+/* returns true if hardware supports Intel Processor Trace */
+static inline bool hvm_ipt_supported(void)
+{
+ return hvm_funcs.ipt_supported;
+}
+
/* updates the current hardware p2m */
static inline void altp2m_vcpu_update_p2m(struct vcpu *v)
{
diff --git a/xen/include/asm-x86/hvm/vmx/vmcs.h b/xen/include/asm-x86/hvm/vmx/vmcs.h
index 906810592f..4c81093aba 100644
--- a/xen/include/asm-x86/hvm/vmx/vmcs.h
+++ b/xen/include/asm-x86/hvm/vmx/vmcs.h
@@ -285,6 +285,7 @@ extern u64 vmx_ept_vpid_cap;
#define VMX_MISC_CR3_TARGET 0x01ff0000
#define VMX_MISC_VMWRITE_ALL 0x20000000
+#define VMX_MISC_PT_SUPPORTED 0x00004000
#define VMX_TSC_MULTIPLIER_MAX 0xffffffffffffffffULL
diff --git a/xen/include/public/arch-x86/cpufeatureset.h b/xen/include/public/arch-x86/cpufeatureset.h
index 5ca35d9d97..7cfcac451d 100644
--- a/xen/include/public/arch-x86/cpufeatureset.h
+++ b/xen/include/public/arch-x86/cpufeatureset.h
@@ -217,6 +217,7 @@ XEN_CPUFEATURE(SMAP, 5*32+20) /*S Supervisor Mode Access Prevention */
XEN_CPUFEATURE(AVX512_IFMA, 5*32+21) /*A AVX-512 Integer Fused Multiply Add */
XEN_CPUFEATURE(CLFLUSHOPT, 5*32+23) /*A CLFLUSHOPT instruction */
XEN_CPUFEATURE(CLWB, 5*32+24) /*A CLWB instruction */
+XEN_CPUFEATURE(IPT, 5*32+25) /*H Intel Processor Trace */
XEN_CPUFEATURE(AVX512PF, 5*32+26) /*A AVX-512 Prefetch Instructions */
XEN_CPUFEATURE(AVX512ER, 5*32+27) /*A AVX-512 Exponent & Reciprocal Instrs */
XEN_CPUFEATURE(AVX512CD, 5*32+28) /*A AVX-512 Conflict Detection Instrs */
--
2.20.1
On Tue, Jun 16, 2020 at 05:20:39PM +0200, Michał Leszczyński wrote:
> Check if Intel Processor Trace feature is supported by current
> processor. Define hvm_ipt_supported function.
>
> Signed-off-by: Michal Leszczynski <michal.leszczynski@cert.pl>
> ---
> xen/arch/x86/hvm/vmx/vmx.c | 24 +++++++++++++++++++++
> xen/include/asm-x86/cpufeature.h | 1 +
> xen/include/asm-x86/hvm/hvm.h | 9 ++++++++
> xen/include/asm-x86/hvm/vmx/vmcs.h | 1 +
> xen/include/public/arch-x86/cpufeatureset.h | 1 +
> 5 files changed, 36 insertions(+)
>
> diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
> index ab19d9424e..a91bbdb798 100644
> --- a/xen/arch/x86/hvm/vmx/vmx.c
> +++ b/xen/arch/x86/hvm/vmx/vmx.c
> @@ -2484,6 +2484,7 @@ static bool __init has_if_pschange_mc(void)
>
> const struct hvm_function_table * __init start_vmx(void)
> {
> + u64 _vmx_misc_cap;
Please use uint64_t, and you can drop the leading _vmx prefix, this is
already vmx specific. Also add a newline between variable definition
and code.
> set_in_cr4(X86_CR4_VMXE);
>
> if ( vmx_vmcs_init() )
> @@ -2557,6 +2558,29 @@ const struct hvm_function_table * __init start_vmx(void)
> vmx_function_table.get_guest_bndcfgs = vmx_get_guest_bndcfgs;
> }
>
> + /* Check whether IPT is supported in VMX operation */
> + vmx_function_table.ipt_supported = 1;
> +
> + if ( !cpu_has_ipt )
> + {
> + vmx_function_table.ipt_supported = 0;
> + printk("VMX: Missing support for Intel Processor Trace x86 feature.\n");
> + }
> +
> + rdmsrl(MSR_IA32_VMX_MISC, _vmx_misc_cap);
> +
> + if ( !( _vmx_misc_cap & VMX_MISC_PT_SUPPORTED ) )
> + {
> + vmx_function_table.ipt_supported = 0;
> + printk("VMX: Missing support for Intel Processor Trace in VMX operation, VMX_MISC caps: %llx\n",
> + (unsigned long long)_vmx_misc_cap);
> + }
> +
> + if (vmx_function_table.ipt_supported)
> + {
> + printk("VMX: Intel Processor Trace is SUPPORTED");
> + }
I think you could simplify this as:
vmx_function_table.ipt_supported = cpu_has_ipt &&
(misc_cap & VMX_MISC_PT_SUPPORTED);
Also the code is too chatty IMO.
Looking at how other VMX features are detected, I think you should
move the checks to vmx_init_vmcs_config and set the relevant bits in
the VM control registers that you can then evaluate in
vmx_display_features in order to print if the feature is supported?
> +
> lbr_tsx_fixup_check();
> ler_to_fixup_check();
>
> diff --git a/xen/include/asm-x86/cpufeature.h b/xen/include/asm-x86/cpufeature.h
> index f790d5c1f8..8d7955dd87 100644
> --- a/xen/include/asm-x86/cpufeature.h
> +++ b/xen/include/asm-x86/cpufeature.h
> @@ -104,6 +104,7 @@
> #define cpu_has_clwb boot_cpu_has(X86_FEATURE_CLWB)
> #define cpu_has_avx512er boot_cpu_has(X86_FEATURE_AVX512ER)
> #define cpu_has_avx512cd boot_cpu_has(X86_FEATURE_AVX512CD)
> +#define cpu_has_ipt boot_cpu_has(X86_FEATURE_IPT)
> #define cpu_has_sha boot_cpu_has(X86_FEATURE_SHA)
> #define cpu_has_avx512bw boot_cpu_has(X86_FEATURE_AVX512BW)
> #define cpu_has_avx512vl boot_cpu_has(X86_FEATURE_AVX512VL)
> diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
> index 1eb377dd82..48465b6067 100644
> --- a/xen/include/asm-x86/hvm/hvm.h
> +++ b/xen/include/asm-x86/hvm/hvm.h
> @@ -96,6 +96,9 @@ struct hvm_function_table {
> /* Necessary hardware support for alternate p2m's? */
> bool altp2m_supported;
>
> + /* Hardware support for IPT? */
> + bool ipt_supported;
We might want to name this pt_supported, since it's possible for other
vendors to also introduce a processor tracing feature in the future?
Thanks, Roger.
On 16.06.2020 18:30, Roger Pau Monné wrote:
> On Tue, Jun 16, 2020 at 05:20:39PM +0200, Michał Leszczyński wrote:
>> Check if Intel Processor Trace feature is supported by current
>> processor. Define hvm_ipt_supported function.
>>
>> Signed-off-by: Michal Leszczynski <michal.leszczynski@cert.pl>
>> ---
>> xen/arch/x86/hvm/vmx/vmx.c | 24 +++++++++++++++++++++
>> xen/include/asm-x86/cpufeature.h | 1 +
>> xen/include/asm-x86/hvm/hvm.h | 9 ++++++++
>> xen/include/asm-x86/hvm/vmx/vmcs.h | 1 +
>> xen/include/public/arch-x86/cpufeatureset.h | 1 +
>> 5 files changed, 36 insertions(+)
>>
>> diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
>> index ab19d9424e..a91bbdb798 100644
>> --- a/xen/arch/x86/hvm/vmx/vmx.c
>> +++ b/xen/arch/x86/hvm/vmx/vmx.c
>> @@ -2484,6 +2484,7 @@ static bool __init has_if_pschange_mc(void)
>>
>> const struct hvm_function_table * __init start_vmx(void)
>> {
>> + u64 _vmx_misc_cap;
>
> Please use uint64_t, and you can drop the leading _vmx prefix, this is
> already vmx specific.
Actually, all of _vmx_ should be dropped (i.e. in particular local
variables shouldn't start with an underscore).
Jan
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