2022-03-04 20:09:05

by Isaku Yamahata

[permalink] [raw]
Subject: [RFC PATCH v5 020/104] KVM: TDX: allocate per-package mutex

From: Isaku Yamahata <[email protected]>

Several TDX SEAMCALLs are per-package scope (concretely per memory
controller) and they need to be serialized per-package. Allocate mutex for
it.

Signed-off-by: Isaku Yamahata <[email protected]>
---
arch/x86/kvm/vmx/main.c | 8 +++++++-
arch/x86/kvm/vmx/tdx.c | 18 ++++++++++++++++++
arch/x86/kvm/vmx/x86_ops.h | 2 ++
3 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 8103d1c32cc9..6111c6485d8e 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -25,6 +25,12 @@ static __init int vt_hardware_setup(void)
return 0;
}

+static void vt_hardware_unsetup(void)
+{
+ tdx_hardware_unsetup();
+ vmx_hardware_unsetup();
+}
+
static int vt_vm_init(struct kvm *kvm)
{
int ret;
@@ -42,7 +48,7 @@ static int vt_vm_init(struct kvm *kvm)
struct kvm_x86_ops vt_x86_ops __initdata = {
.name = "kvm_intel",

- .hardware_unsetup = vmx_hardware_unsetup,
+ .hardware_unsetup = vt_hardware_unsetup,

.hardware_enable = vmx_hardware_enable,
.hardware_disable = vmx_hardware_disable,
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index e8d293a3c11c..1c8222f54764 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -34,6 +34,8 @@ struct tdx_capabilities {
/* Capabilities of KVM + the TDX module. */
struct tdx_capabilities tdx_caps;

+static struct mutex *tdx_mng_key_config_lock;
+
static u64 hkid_mask __ro_after_init;
static u8 hkid_start_pos __ro_after_init;

@@ -112,7 +114,9 @@ bool tdx_is_vm_type_supported(unsigned long type)

static int __init __tdx_hardware_setup(struct kvm_x86_ops *x86_ops)
{
+ int max_pkgs;
u32 max_pa;
+ int i;

if (!enable_ept) {
pr_warn("Cannot enable TDX with EPT disabled\n");
@@ -127,6 +131,14 @@ static int __init __tdx_hardware_setup(struct kvm_x86_ops *x86_ops)
if (WARN_ON_ONCE(x86_ops->tlb_remote_flush))
return -EIO;

+ max_pkgs = topology_max_packages();
+ tdx_mng_key_config_lock = kcalloc(max_pkgs, sizeof(*tdx_mng_key_config_lock),
+ GFP_KERNEL);
+ if (!tdx_mng_key_config_lock)
+ return -ENOMEM;
+ for (i = 0; i < max_pkgs; i++)
+ mutex_init(&tdx_mng_key_config_lock[i]);
+
max_pa = cpuid_eax(0x80000008) & 0xff;
hkid_start_pos = boot_cpu_data.x86_phys_bits;
hkid_mask = GENMASK_ULL(max_pa - 1, hkid_start_pos);
@@ -147,6 +159,12 @@ void __init tdx_hardware_setup(struct kvm_x86_ops *x86_ops)
enable_tdx = false;
}

+void tdx_hardware_unsetup(void)
+{
+ /* kfree accepts NULL. */
+ kfree(tdx_mng_key_config_lock);
+}
+
void __init tdx_pre_kvm_init(unsigned int *vcpu_size,
unsigned int *vcpu_align, unsigned int *vm_size)
{
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index 78331dbc29f7..da32b4b86b19 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -131,11 +131,13 @@ void __init tdx_pre_kvm_init(unsigned int *vcpu_size,
unsigned int *vcpu_align, unsigned int *vm_size);
bool tdx_is_vm_type_supported(unsigned long type);
void __init tdx_hardware_setup(struct kvm_x86_ops *x86_ops);
+void tdx_hardware_unsetup(void);
#else
static inline void tdx_pre_kvm_init(
unsigned int *vcpu_size, unsigned int *vcpu_align, unsigned int *vm_size) {}
static inline bool tdx_is_vm_type_supported(unsigned long type) { return false; }
static inline void tdx_hardware_setup(struct kvm_x86_ops *x86_ops) {}
+static inline void tdx_hardware_unsetup(void) {}
#endif

#endif /* __KVM_X86_VMX_X86_OPS_H */
--
2.25.1


2022-04-06 13:45:16

by Paolo Bonzini

[permalink] [raw]
Subject: Re: [RFC PATCH v5 020/104] KVM: TDX: allocate per-package mutex

On 3/4/22 20:48, [email protected] wrote:
> From: Isaku Yamahata <[email protected]>
>
> Several TDX SEAMCALLs are per-package scope (concretely per memory
> controller) and they need to be serialized per-package. Allocate mutex for
> it.
>
> Signed-off-by: Isaku Yamahata <[email protected]>
> ---
> arch/x86/kvm/vmx/main.c | 8 +++++++-
> arch/x86/kvm/vmx/tdx.c | 18 ++++++++++++++++++
> arch/x86/kvm/vmx/x86_ops.h | 2 ++
> 3 files changed, 27 insertions(+), 1 deletion(-)

Please define here the lock/unlock functions as well:

static inline int tdx_mng_key_lock(void)
{
int cpu = get_cpu();
cur_pkg = topology_physical_package_id(cpu);

mutex_lock(&tdx_mng_key_config_lock[cur_pkg]);
return cur_pkg;
}

static inline void tdx_mng_key_unlock(int cur_pkg)
{
mutex_unlock(&tdx_mng_key_config_lock[cur_pkg]);
put_cpu();
}

Thanks,

Paolo


>
> diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
> index 8103d1c32cc9..6111c6485d8e 100644
> --- a/arch/x86/kvm/vmx/main.c
> +++ b/arch/x86/kvm/vmx/main.c
> @@ -25,6 +25,12 @@ static __init int vt_hardware_setup(void)
> return 0;
> }
>
> +static void vt_hardware_unsetup(void)
> +{
> + tdx_hardware_unsetup();
> + vmx_hardware_unsetup();
> +}
> +
> static int vt_vm_init(struct kvm *kvm)
> {
> int ret;
> @@ -42,7 +48,7 @@ static int vt_vm_init(struct kvm *kvm)
> struct kvm_x86_ops vt_x86_ops __initdata = {
> .name = "kvm_intel",
>
> - .hardware_unsetup = vmx_hardware_unsetup,
> + .hardware_unsetup = vt_hardware_unsetup,
>
> .hardware_enable = vmx_hardware_enable,
> .hardware_disable = vmx_hardware_disable,
> diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
> index e8d293a3c11c..1c8222f54764 100644
> --- a/arch/x86/kvm/vmx/tdx.c
> +++ b/arch/x86/kvm/vmx/tdx.c
> @@ -34,6 +34,8 @@ struct tdx_capabilities {
> /* Capabilities of KVM + the TDX module. */
> struct tdx_capabilities tdx_caps;
>
> +static struct mutex *tdx_mng_key_config_lock;
> +
> static u64 hkid_mask __ro_after_init;
> static u8 hkid_start_pos __ro_after_init;
>
> @@ -112,7 +114,9 @@ bool tdx_is_vm_type_supported(unsigned long type)
>
> static int __init __tdx_hardware_setup(struct kvm_x86_ops *x86_ops)
> {
> + int max_pkgs;
> u32 max_pa;
> + int i;
>
> if (!enable_ept) {
> pr_warn("Cannot enable TDX with EPT disabled\n");
> @@ -127,6 +131,14 @@ static int __init __tdx_hardware_setup(struct kvm_x86_ops *x86_ops)
> if (WARN_ON_ONCE(x86_ops->tlb_remote_flush))
> return -EIO;
>
> + max_pkgs = topology_max_packages();
> + tdx_mng_key_config_lock = kcalloc(max_pkgs, sizeof(*tdx_mng_key_config_lock),
> + GFP_KERNEL);
> + if (!tdx_mng_key_config_lock)
> + return -ENOMEM;
> + for (i = 0; i < max_pkgs; i++)
> + mutex_init(&tdx_mng_key_config_lock[i]);
> +
> max_pa = cpuid_eax(0x80000008) & 0xff;
> hkid_start_pos = boot_cpu_data.x86_phys_bits;
> hkid_mask = GENMASK_ULL(max_pa - 1, hkid_start_pos);
> @@ -147,6 +159,12 @@ void __init tdx_hardware_setup(struct kvm_x86_ops *x86_ops)
> enable_tdx = false;
> }
>
> +void tdx_hardware_unsetup(void)
> +{
> + /* kfree accepts NULL. */
> + kfree(tdx_mng_key_config_lock);
> +}
> +
> void __init tdx_pre_kvm_init(unsigned int *vcpu_size,
> unsigned int *vcpu_align, unsigned int *vm_size)
> {
> diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
> index 78331dbc29f7..da32b4b86b19 100644
> --- a/arch/x86/kvm/vmx/x86_ops.h
> +++ b/arch/x86/kvm/vmx/x86_ops.h
> @@ -131,11 +131,13 @@ void __init tdx_pre_kvm_init(unsigned int *vcpu_size,
> unsigned int *vcpu_align, unsigned int *vm_size);
> bool tdx_is_vm_type_supported(unsigned long type);
> void __init tdx_hardware_setup(struct kvm_x86_ops *x86_ops);
> +void tdx_hardware_unsetup(void);
> #else
> static inline void tdx_pre_kvm_init(
> unsigned int *vcpu_size, unsigned int *vcpu_align, unsigned int *vm_size) {}
> static inline bool tdx_is_vm_type_supported(unsigned long type) { return false; }
> static inline void tdx_hardware_setup(struct kvm_x86_ops *x86_ops) {}
> +static inline void tdx_hardware_unsetup(void) {}
> #endif
>
> #endif /* __KVM_X86_VMX_X86_OPS_H */

2022-04-08 01:13:37

by Isaku Yamahata

[permalink] [raw]
Subject: Re: [RFC PATCH v5 020/104] KVM: TDX: allocate per-package mutex

On Tue, Apr 05, 2022 at 02:39:51PM +0200,
Paolo Bonzini <[email protected]> wrote:

> On 3/4/22 20:48, [email protected] wrote:
> > From: Isaku Yamahata <[email protected]>
> >
> > Several TDX SEAMCALLs are per-package scope (concretely per memory
> > controller) and they need to be serialized per-package. Allocate mutex for
> > it.
> >
> > Signed-off-by: Isaku Yamahata <[email protected]>
> > ---
> > arch/x86/kvm/vmx/main.c | 8 +++++++-
> > arch/x86/kvm/vmx/tdx.c | 18 ++++++++++++++++++
> > arch/x86/kvm/vmx/x86_ops.h | 2 ++
> > 3 files changed, 27 insertions(+), 1 deletion(-)
>
> Please define here the lock/unlock functions as well:
>
> static inline int tdx_mng_key_lock(void)
> {
> int cpu = get_cpu();
> cur_pkg = topology_physical_package_id(cpu);
>
> mutex_lock(&tdx_mng_key_config_lock[cur_pkg]);
> return cur_pkg;
> }
>
> static inline void tdx_mng_key_unlock(int cur_pkg)
> {
> mutex_unlock(&tdx_mng_key_config_lock[cur_pkg]);
> put_cpu();
> }

Sure, will do in the next respoin.
--
Isaku Yamahata <[email protected]>