Re: [PATCH v6 3/9] KVM: VMX: Detect Tertiary VM-Execution control when setup VMCS config

Maxim Levitsky
2022-02-25T14:30:37Z

On Fri, 2022-02-25 at 16:22 +0800, Zeng Guang wrote:
> From: Robert Hoo <robert.hu@linux.intel.com>
>
> Check VMX features on tertiary execution control in VMCS config setup.
> Sub-features in tertiary execution control to be enabled are adjusted
> according to hardware capabilities although no sub-feature is enabled
> in this patch.
>
> EVMCSv1 doesn't support tertiary VM-execution control, so disable it
> when EVMCSv1 is in use. And define the auxiliary functions for Tertiary
> control field here, using the new BUILD_CONTROLS_SHADOW().
>
> Signed-off-by: Robert Hoo <robert.hu@linux.intel.com>
> Signed-off-by: Zeng Guang <guang.zeng@intel.com>
> ---
> arch/x86/include/asm/vmx.h | 3 +++
> arch/x86/kvm/vmx/capabilities.h | 7 ++++++
> arch/x86/kvm/vmx/evmcs.c | 2 ++
> arch/x86/kvm/vmx/evmcs.h | 1 +
> arch/x86/kvm/vmx/vmcs.h | 1 +
> arch/x86/kvm/vmx/vmx.c | 38 ++++++++++++++++++++++++++++++++-
> arch/x86/kvm/vmx/vmx.h | 1 +
> 7 files changed, 52 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
> index 0ffaa3156a4e..8c929596a299 100644
> --- a/arch/x86/include/asm/vmx.h
> +++ b/arch/x86/include/asm/vmx.h
> @@ -31,6 +31,7 @@
> #define CPU_BASED_RDTSC_EXITING VMCS_CONTROL_BIT(RDTSC_EXITING)
> #define CPU_BASED_CR3_LOAD_EXITING VMCS_CONTROL_BIT(CR3_LOAD_EXITING)
> #define CPU_BASED_CR3_STORE_EXITING VMCS_CONTROL_BIT(CR3_STORE_EXITING)
> +#define CPU_BASED_ACTIVATE_TERTIARY_CONTROLS VMCS_CONTROL_BIT(TERTIARY_CONTROLS)
> #define CPU_BASED_CR8_LOAD_EXITING VMCS_CONTROL_BIT(CR8_LOAD_EXITING)
> #define CPU_BASED_CR8_STORE_EXITING VMCS_CONTROL_BIT(CR8_STORE_EXITING)
> #define CPU_BASED_TPR_SHADOW VMCS_CONTROL_BIT(VIRTUAL_TPR)
> @@ -221,6 +222,8 @@ enum vmcs_field {
> ENCLS_EXITING_BITMAP_HIGH = 0x0000202F,
> TSC_MULTIPLIER = 0x00002032,
> TSC_MULTIPLIER_HIGH = 0x00002033,
> + TERTIARY_VM_EXEC_CONTROL = 0x00002034,
> + TERTIARY_VM_EXEC_CONTROL_HIGH = 0x00002035,
> GUEST_PHYSICAL_ADDRESS = 0x00002400,
> GUEST_PHYSICAL_ADDRESS_HIGH = 0x00002401,
> VMCS_LINK_POINTER = 0x00002800,
> diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
> index 3f430e218375..31f3d88b3e4d 100644
> --- a/arch/x86/kvm/vmx/capabilities.h
> +++ b/arch/x86/kvm/vmx/capabilities.h
> @@ -59,6 +59,7 @@ struct vmcs_config {
> u32 pin_based_exec_ctrl;
> u32 cpu_based_exec_ctrl;
> u32 cpu_based_2nd_exec_ctrl;
> + u64 cpu_based_3rd_exec_ctrl;
> u32 vmexit_ctrl;
> u32 vmentry_ctrl;
> struct nested_vmx_msrs nested;
> @@ -131,6 +132,12 @@ static inline bool cpu_has_secondary_exec_ctrls(void)
> CPU_BASED_ACTIVATE_SECONDARY_CONTROLS;
> }
>
> +static inline bool cpu_has_tertiary_exec_ctrls(void)
> +{
> + return vmcs_config.cpu_based_exec_ctrl &
> + CPU_BASED_ACTIVATE_TERTIARY_CONTROLS;
> +}
> +
> static inline bool cpu_has_vmx_virtualize_apic_accesses(void)
> {
> return vmcs_config.cpu_based_2nd_exec_ctrl &
> diff --git a/arch/x86/kvm/vmx/evmcs.c b/arch/x86/kvm/vmx/evmcs.c
> index 87e3dc10edf4..6a61b1ae7942 100644
> --- a/arch/x86/kvm/vmx/evmcs.c
> +++ b/arch/x86/kvm/vmx/evmcs.c
> @@ -297,8 +297,10 @@ const unsigned int nr_evmcs_1_fields = ARRAY_SIZE(vmcs_field_to_evmcs_1);
> #if IS_ENABLED(CONFIG_HYPERV)
> __init void evmcs_sanitize_exec_ctrls(struct vmcs_config *vmcs_conf)
> {
> + vmcs_conf->cpu_based_exec_ctrl &= ~EVMCS1_UNSUPPORTED_EXEC_CTRL;
> vmcs_conf->pin_based_exec_ctrl &= ~EVMCS1_UNSUPPORTED_PINCTRL;
> vmcs_conf->cpu_based_2nd_exec_ctrl &= ~EVMCS1_UNSUPPORTED_2NDEXEC;
> + vmcs_conf->cpu_based_3rd_exec_ctrl = 0;
>
> vmcs_conf->vmexit_ctrl &= ~EVMCS1_UNSUPPORTED_VMEXIT_CTRL;
> vmcs_conf->vmentry_ctrl &= ~EVMCS1_UNSUPPORTED_VMENTRY_CTRL;
> diff --git a/arch/x86/kvm/vmx/evmcs.h b/arch/x86/kvm/vmx/evmcs.h
> index 8d70f9aea94b..f886a8ff0342 100644
> --- a/arch/x86/kvm/vmx/evmcs.h
> +++ b/arch/x86/kvm/vmx/evmcs.h
> @@ -50,6 +50,7 @@ DECLARE_STATIC_KEY_FALSE(enable_evmcs);
> */
> #define EVMCS1_UNSUPPORTED_PINCTRL (PIN_BASED_POSTED_INTR | \
> PIN_BASED_VMX_PREEMPTION_TIMER)
> +#define EVMCS1_UNSUPPORTED_EXEC_CTRL (CPU_BASED_ACTIVATE_TERTIARY_CONTROLS)
> #define EVMCS1_UNSUPPORTED_2NDEXEC \
> (SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY | \
> SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES | \
> diff --git a/arch/x86/kvm/vmx/vmcs.h b/arch/x86/kvm/vmx/vmcs.h
> index e325c290a816..e18dc68eeeeb 100644
> --- a/arch/x86/kvm/vmx/vmcs.h
> +++ b/arch/x86/kvm/vmx/vmcs.h
> @@ -50,6 +50,7 @@ struct vmcs_controls_shadow {
> u32 pin;
> u32 exec;
> u32 secondary_exec;
> + u64 tertiary_exec;
> };
>
> /*
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index c569dc2b9192..8a5713d49635 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -2422,6 +2422,21 @@ static __init int adjust_vmx_controls(u32 ctl_min, u32 ctl_opt,
> return 0;
> }
>
> +static __init int adjust_vmx_controls_64(u64 ctl_min, u64 ctl_opt,
> + u32 msr, u64 *result)
> +{
> + u64 allowed1;
> +
> + rdmsrl(msr, allowed1);
> +
> + /* Ensure minimum (required) set of control bits are supported. */
> + if (ctl_min & ~allowed1)
> + return -EIO;
> +
> + *result = (ctl_min | ctl_opt) & allowed1;
> + return 0;
> +}
> +
> static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
> struct vmx_capability *vmx_cap)
> {
> @@ -2430,6 +2445,7 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
> u32 _pin_based_exec_control = 0;
> u32 _cpu_based_exec_control = 0;
> u32 _cpu_based_2nd_exec_control = 0;
> + u64 _cpu_based_3rd_exec_control = 0;
> u32 _vmexit_control = 0;
> u32 _vmentry_control = 0;
>
> @@ -2451,7 +2467,8 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
>
> opt = CPU_BASED_TPR_SHADOW |
> CPU_BASED_USE_MSR_BITMAPS |
> - CPU_BASED_ACTIVATE_SECONDARY_CONTROLS;
> + CPU_BASED_ACTIVATE_SECONDARY_CONTROLS |
> + CPU_BASED_ACTIVATE_TERTIARY_CONTROLS;
> if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_PROCBASED_CTLS,
> &_cpu_based_exec_control) < 0)
> return -EIO;
> @@ -2525,6 +2542,16 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
> "1-setting enable VPID VM-execution control\n");
> }
>
> + if (_cpu_based_exec_control & CPU_BASED_ACTIVATE_TERTIARY_CONTROLS) {
> + u64 opt3 = 0;
> + u64 min3 = 0;
> +
> + if (adjust_vmx_controls_64(min3, opt3,
> + MSR_IA32_VMX_PROCBASED_CTLS3,
> + &_cpu_based_3rd_exec_control))
> + return -EIO;
> + }
> +
> min = VM_EXIT_SAVE_DEBUG_CONTROLS | VM_EXIT_ACK_INTR_ON_EXIT;
> #ifdef CONFIG_X86_64
> min |= VM_EXIT_HOST_ADDR_SPACE_SIZE;
> @@ -2611,6 +2638,7 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
> vmcs_conf->pin_based_exec_ctrl = _pin_based_exec_control;
> vmcs_conf->cpu_based_exec_ctrl = _cpu_based_exec_control;
> vmcs_conf->cpu_based_2nd_exec_ctrl = _cpu_based_2nd_exec_control;
> + vmcs_conf->cpu_based_3rd_exec_ctrl = _cpu_based_3rd_exec_control;
> vmcs_conf->vmexit_ctrl = _vmexit_control;
> vmcs_conf->vmentry_ctrl = _vmentry_control;
>
> @@ -4230,6 +4258,11 @@ static u32 vmx_exec_control(struct vcpu_vmx *vmx)
> return exec_control;
> }
>
> +static u64 vmx_tertiary_exec_control(struct vcpu_vmx *vmx)
> +{
> + return vmcs_config.cpu_based_3rd_exec_ctrl;
> +}
> +
> /*
> * Adjust a single secondary execution control bit to intercept/allow an
> * instruction in the guest. This is usually done based on whether or not a
> @@ -4395,6 +4428,9 @@ static void init_vmcs(struct vcpu_vmx *vmx)
> if (cpu_has_secondary_exec_ctrls())
> secondary_exec_controls_set(vmx, vmx_secondary_exec_control(vmx));
>
> + if (cpu_has_tertiary_exec_ctrls())
> + tertiary_exec_controls_set(vmx, vmx_tertiary_exec_control(vmx));
> +
> if (kvm_vcpu_apicv_active(&vmx->vcpu)) {
> vmcs_write64(EOI_EXIT_BITMAP0, 0);
> vmcs_write64(EOI_EXIT_BITMAP1, 0);
> diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
> index e07c76974fb0..d4a647d3ed4a 100644
> --- a/arch/x86/kvm/vmx/vmx.h
> +++ b/arch/x86/kvm/vmx/vmx.h
> @@ -488,6 +488,7 @@ BUILD_CONTROLS_SHADOW(vm_exit, VM_EXIT_CONTROLS, 32)
> BUILD_CONTROLS_SHADOW(pin, PIN_BASED_VM_EXEC_CONTROL, 32)
> BUILD_CONTROLS_SHADOW(exec, CPU_BASED_VM_EXEC_CONTROL, 32)
> BUILD_CONTROLS_SHADOW(secondary_exec, SECONDARY_VM_EXEC_CONTROL, 32)
> +BUILD_CONTROLS_SHADOW(tertiary_exec, TERTIARY_VM_EXEC_CONTROL, 64)
>
> /*
> * VMX_REGS_LAZY_LOAD_SET - The set of registers that will be updated in the

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>

Best regards,
Maxim Levitsky