| Message ID | 4b8921da8e0d037b1e99d5cc92eea8f8470cf2e0.1613221549.git.kai.huang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM SGX virtualization support | expand |
On Sun, Feb 14, 2021 at 02:29:15AM +1300, Kai Huang wrote: > From: Sean Christopherson <sean.j.christopherson@intel.com> > > The host kernel must intercept ECREATE to be able to impose policies on > guests. When it does this, the host kernel runs ECREATE against the > userspace mapping of the virtualized EPC. > > Provide wrappers around __ecreate() and __einit() to hide the ugliness > of overloading the ENCLS return value to encode multiple error formats > in a single int. KVM will trap-and-execute ECREATE and EINIT as part > of SGX virtualization, and on an exception, KVM needs the trapnr so that > it can inject the correct fault into the guest. > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > Signed-off-by: Kai Huang <kai.huang@intel.com> > --- > v4->v5: > > - No code change. > > v3->v4: > > - Added one new line before last return in sgx_virt_einit(), per Jarkko. > > v2->v3: > > - Added kdoc for sgx_virt_ecreate() and sgx_virt_einit(), per Jarkko. > - Changed to use CONFIG_X86_SGX_KVM. > > --- > arch/x86/include/asm/sgx.h | 16 ++++++ > arch/x86/kernel/cpu/sgx/virt.c | 94 ++++++++++++++++++++++++++++++++++ > 2 files changed, 110 insertions(+) > create mode 100644 arch/x86/include/asm/sgx.h > > diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h > new file mode 100644 > index 000000000000..8a3ea3e1efbe > --- /dev/null > +++ b/arch/x86/include/asm/sgx.h > @@ -0,0 +1,16 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +#ifndef _ASM_X86_SGX_H > +#define _ASM_X86_SGX_H > + > +#include <linux/types.h> > + > +#ifdef CONFIG_X86_SGX_KVM > +struct sgx_pageinfo; > + > +int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs, > + int *trapnr); > +int sgx_virt_einit(void __user *sigstruct, void __user *token, > + void __user *secs, u64 *lepubkeyhash, int *trapnr); s/virt/vepc/g > +#endif > + > +#endif /* _ASM_X86_SGX_H */ > diff --git a/arch/x86/kernel/cpu/sgx/virt.c b/arch/x86/kernel/cpu/sgx/virt.c > index 47542140f8c1..016bad7cff8d 100644 > --- a/arch/x86/kernel/cpu/sgx/virt.c > +++ b/arch/x86/kernel/cpu/sgx/virt.c Rename as vepc.c. > @@ -257,3 +257,97 @@ int __init sgx_vepc_init(void) > > return misc_register(&sgx_vepc_dev); > } > + > +/** > + * sgx_virt_ecreate() - Run ECREATE on behalf of guest > + * @pageinfo: Pointer to PAGEINFO structure > + * @secs: Userspace pointer to SECS page > + * @trapnr: trap number injected to guest in case of ECREATE error > + * > + * Run ECREATE on behalf of guest after KVM traps ECREATE for the purpose > + * of enforcing policies of guest's enclaves, and return the trap number > + * which should be injected to guest in case of any ECREATE error. > + * > + * Return: > + * - 0: ECREATE was successful. > + * - -EFAULT: ECREATE returned error. > + */ > +int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs, > + int *trapnr) > +{ > + int ret; > + > + /* > + * @secs is userspace address, and it's not guaranteed @secs points at > + * an actual EPC page. It's also possible to generate a kernel mapping > + * to physical EPC page by resolving PFN but using __uaccess_xx() is > + * simpler. > + */ > + __uaccess_begin(); > + ret = __ecreate(pageinfo, (void *)secs); > + __uaccess_end(); > + > + if (encls_faulted(ret)) { > + *trapnr = ENCLS_TRAPNR(ret); > + return -EFAULT; > + } > + > + /* ECREATE doesn't return an error code, it faults or succeeds. */ > + WARN_ON_ONCE(ret); Empty line. > + return 0; > +} > +EXPORT_SYMBOL_GPL(sgx_virt_ecreate); > + > +static int __sgx_virt_einit(void __user *sigstruct, void __user *token, > + void __user *secs) > +{ > + int ret; > + > + __uaccess_begin(); > + ret = __einit((void *)sigstruct, (void *)token, (void *)secs); > + __uaccess_end(); Ditto. > + return ret; > +} > + > +/** > + * sgx_virt_einit() - Run EINIT on behalf of guest > + * @sigstruct: Userspace pointer to SIGSTRUCT structure > + * @token: Userspace pointer to EINITTOKEN structure > + * @secs: Userspace pointer to SECS page > + * @lepubkeyhash: Pointer to guest's *virtual* SGX_LEPUBKEYHASH MSR > + * values > + * @trapnr: trap number injected to guest in case of EINIT error > + * > + * Run EINIT on behalf of guest after KVM traps EINIT. If SGX_LC is available > + * in host, SGX driver may rewrite the hardware values at wish, therefore KVM > + * needs to update hardware values to guest's virtual MSR values in order to > + * ensure EINIT is executed with expected hardware values. > + * > + * Return: > + * - 0: EINIT was successful. > + * - -EFAULT: EINIT returned error. > + */ > +int sgx_virt_einit(void __user *sigstruct, void __user *token, > + void __user *secs, u64 *lepubkeyhash, int *trapnr) > +{ > + int ret; > + > + if (!boot_cpu_has(X86_FEATURE_SGX_LC)) { > + ret = __sgx_virt_einit(sigstruct, token, secs); > + } else { > + preempt_disable(); > + > + sgx_update_lepubkeyhash(lepubkeyhash); > + > + ret = __sgx_virt_einit(sigstruct, token, secs); > + preempt_enable(); > + } > + > + if (encls_faulted(ret)) { > + *trapnr = ENCLS_TRAPNR(ret); > + return -EFAULT; > + } > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(sgx_virt_einit); > -- > 2.29.2 > > /Jarkko
On Tue, Feb 16, 2021 at 05:08:20AM +0200, Jarkko Sakkinen wrote: > On Sun, Feb 14, 2021 at 02:29:15AM +1300, Kai Huang wrote: > > From: Sean Christopherson <sean.j.christopherson@intel.com> > > > > The host kernel must intercept ECREATE to be able to impose policies on > > guests. When it does this, the host kernel runs ECREATE against the > > userspace mapping of the virtualized EPC. > > > > Provide wrappers around __ecreate() and __einit() to hide the ugliness > > of overloading the ENCLS return value to encode multiple error formats > > in a single int. KVM will trap-and-execute ECREATE and EINIT as part > > of SGX virtualization, and on an exception, KVM needs the trapnr so that > > it can inject the correct fault into the guest. > > > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > > Signed-off-by: Kai Huang <kai.huang@intel.com> > > --- > > v4->v5: > > > > - No code change. > > > > v3->v4: > > > > - Added one new line before last return in sgx_virt_einit(), per Jarkko. > > > > v2->v3: > > > > - Added kdoc for sgx_virt_ecreate() and sgx_virt_einit(), per Jarkko. > > - Changed to use CONFIG_X86_SGX_KVM. > > > > --- > > arch/x86/include/asm/sgx.h | 16 ++++++ > > arch/x86/kernel/cpu/sgx/virt.c | 94 ++++++++++++++++++++++++++++++++++ > > 2 files changed, 110 insertions(+) > > create mode 100644 arch/x86/include/asm/sgx.h > > > > diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h > > new file mode 100644 > > index 000000000000..8a3ea3e1efbe > > --- /dev/null > > +++ b/arch/x86/include/asm/sgx.h > > @@ -0,0 +1,16 @@ > > +/* SPDX-License-Identifier: GPL-2.0 */ > > +#ifndef _ASM_X86_SGX_H > > +#define _ASM_X86_SGX_H > > + > > +#include <linux/types.h> > > + > > +#ifdef CONFIG_X86_SGX_KVM > > +struct sgx_pageinfo; > > + > > +int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs, > > + int *trapnr); > > +int sgx_virt_einit(void __user *sigstruct, void __user *token, > > + void __user *secs, u64 *lepubkeyhash, int *trapnr); > > s/virt/vepc/g > > > +#endif > > + > > +#endif /* _ASM_X86_SGX_H */ > > diff --git a/arch/x86/kernel/cpu/sgx/virt.c b/arch/x86/kernel/cpu/sgx/virt.c > > index 47542140f8c1..016bad7cff8d 100644 > > --- a/arch/x86/kernel/cpu/sgx/virt.c > > +++ b/arch/x86/kernel/cpu/sgx/virt.c > > Rename as vepc.c. > > > @@ -257,3 +257,97 @@ int __init sgx_vepc_init(void) > > > > return misc_register(&sgx_vepc_dev); > > } > > + > > +/** > > + * sgx_virt_ecreate() - Run ECREATE on behalf of guest > > + * @pageinfo: Pointer to PAGEINFO structure > > + * @secs: Userspace pointer to SECS page > > + * @trapnr: trap number injected to guest in case of ECREATE error > > + * > > + * Run ECREATE on behalf of guest after KVM traps ECREATE for the purpose > > + * of enforcing policies of guest's enclaves, and return the trap number > > + * which should be injected to guest in case of any ECREATE error. > > + * > > + * Return: > > + * - 0: ECREATE was successful. > > + * - -EFAULT: ECREATE returned error. > > + */ > > +int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs, > > + int *trapnr) > > +{ > > + int ret; > > + > > + /* > > + * @secs is userspace address, and it's not guaranteed @secs points at > > + * an actual EPC page. It's also possible to generate a kernel mapping > > + * to physical EPC page by resolving PFN but using __uaccess_xx() is > > + * simpler. > > + */ > > + __uaccess_begin(); > > + ret = __ecreate(pageinfo, (void *)secs); > > + __uaccess_end(); > > + > > + if (encls_faulted(ret)) { > > + *trapnr = ENCLS_TRAPNR(ret); > > + return -EFAULT; > > + } > > + > > + /* ECREATE doesn't return an error code, it faults or succeeds. */ > > + WARN_ON_ONCE(ret); > > Empty line. > > > + return 0; > > +} > > +EXPORT_SYMBOL_GPL(sgx_virt_ecreate); > > + > > +static int __sgx_virt_einit(void __user *sigstruct, void __user *token, > > + void __user *secs) > > +{ > > + int ret; > > + > > + __uaccess_begin(); > > + ret = __einit((void *)sigstruct, (void *)token, (void *)secs); > > + __uaccess_end(); > > Ditto. > > > + return ret; > > +} > > + > > +/** > > + * sgx_virt_einit() - Run EINIT on behalf of guest > > + * @sigstruct: Userspace pointer to SIGSTRUCT structure > > + * @token: Userspace pointer to EINITTOKEN structure > > + * @secs: Userspace pointer to SECS page > > + * @lepubkeyhash: Pointer to guest's *virtual* SGX_LEPUBKEYHASH MSR > > + * values > > + * @trapnr: trap number injected to guest in case of EINIT error > > + * > > + * Run EINIT on behalf of guest after KVM traps EINIT. If SGX_LC is available > > + * in host, SGX driver may rewrite the hardware values at wish, therefore KVM > > + * needs to update hardware values to guest's virtual MSR values in order to > > + * ensure EINIT is executed with expected hardware values. > > + * > > + * Return: > > + * - 0: EINIT was successful. > > + * - -EFAULT: EINIT returned error. > > + */ > > +int sgx_virt_einit(void __user *sigstruct, void __user *token, > > + void __user *secs, u64 *lepubkeyhash, int *trapnr) > > +{ > > + int ret; > > + > > + if (!boot_cpu_has(X86_FEATURE_SGX_LC)) { > > + ret = __sgx_virt_einit(sigstruct, token, secs); > > + } else { > > + preempt_disable(); > > + > > + sgx_update_lepubkeyhash(lepubkeyhash); > > + > > + ret = __sgx_virt_einit(sigstruct, token, secs); > > + preempt_enable(); > > + } > > + > > + if (encls_faulted(ret)) { > > + *trapnr = ENCLS_TRAPNR(ret); > > + return -EFAULT; > > + } > > + > > + return ret; > > +} > > +EXPORT_SYMBOL_GPL(sgx_virt_einit); Remove exports. > > -- > > 2.29.2 > > > > > > /Jarkko
> > On Tue, Feb 16, 2021 at 05:08:20AM +0200, Jarkko Sakkinen wrote: > > On Sun, Feb 14, 2021 at 02:29:15AM +1300, Kai Huang wrote: > > > From: Sean Christopherson <sean.j.christopherson@intel.com> > > > > > > The host kernel must intercept ECREATE to be able to impose policies > > > on guests. When it does this, the host kernel runs ECREATE against > > > the userspace mapping of the virtualized EPC. > > > > > > Provide wrappers around __ecreate() and __einit() to hide the > > > ugliness of overloading the ENCLS return value to encode multiple > > > error formats in a single int. KVM will trap-and-execute ECREATE > > > and EINIT as part of SGX virtualization, and on an exception, KVM > > > needs the trapnr so that it can inject the correct fault into the guest. > > > > > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > > > Signed-off-by: Kai Huang <kai.huang@intel.com> > > > --- > > > v4->v5: > > > > > > - No code change. > > > > > > v3->v4: > > > > > > - Added one new line before last return in sgx_virt_einit(), per Jarkko. > > > > > > v2->v3: > > > > > > - Added kdoc for sgx_virt_ecreate() and sgx_virt_einit(), per Jarkko. > > > - Changed to use CONFIG_X86_SGX_KVM. > > > > > > --- > > > arch/x86/include/asm/sgx.h | 16 ++++++ > > > arch/x86/kernel/cpu/sgx/virt.c | 94 > > > ++++++++++++++++++++++++++++++++++ > > > 2 files changed, 110 insertions(+) > > > create mode 100644 arch/x86/include/asm/sgx.h > > > > > > diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h > > > new file mode 100644 index 000000000000..8a3ea3e1efbe > > > --- /dev/null > > > +++ b/arch/x86/include/asm/sgx.h > > > @@ -0,0 +1,16 @@ > > > +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_X86_SGX_H > > > +#define _ASM_X86_SGX_H > > > + > > > +#include <linux/types.h> > > > + > > > +#ifdef CONFIG_X86_SGX_KVM > > > +struct sgx_pageinfo; > > > + > > > +int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs, > > > + int *trapnr); > > > +int sgx_virt_einit(void __user *sigstruct, void __user *token, > > > + void __user *secs, u64 *lepubkeyhash, int *trapnr); > > > > s/virt/vepc/g No. The two are related to enclave construction (from guest), not EPC. For instance, what does ECREATE mean for virtual EPC? ECREATE is meaningful for enclave. > > > > > +#endif > > > + > > > +#endif /* _ASM_X86_SGX_H */ > > > diff --git a/arch/x86/kernel/cpu/sgx/virt.c > > > b/arch/x86/kernel/cpu/sgx/virt.c index 47542140f8c1..016bad7cff8d > > > 100644 > > > --- a/arch/x86/kernel/cpu/sgx/virt.c > > > +++ b/arch/x86/kernel/cpu/sgx/virt.c > > > > Rename as vepc.c. No. This file contains more than virtual EPC implementation, but also other staff like sgx_virt_ecreate()/sgx_virt_einit(), which are used by KVM to run ECREATE/EINIT on behalf of guest. > > > > > @@ -257,3 +257,97 @@ int __init sgx_vepc_init(void) > > > > > > return misc_register(&sgx_vepc_dev); } > > > + > > > +/** > > > + * sgx_virt_ecreate() - Run ECREATE on behalf of guest > > > + * @pageinfo: Pointer to PAGEINFO structure > > > + * @secs: Userspace pointer to SECS page > > > + * @trapnr: trap number injected to guest in case of ECREATE error > > > + * > > > + * Run ECREATE on behalf of guest after KVM traps ECREATE for the > > > +purpose > > > + * of enforcing policies of guest's enclaves, and return the trap > > > +number > > > + * which should be injected to guest in case of any ECREATE error. > > > + * > > > + * Return: > > > + * - 0: ECREATE was successful. > > > + * - -EFAULT: ECREATE returned error. > > > + */ > > > +int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs, > > > + int *trapnr) > > > +{ > > > + int ret; > > > + > > > + /* > > > + * @secs is userspace address, and it's not guaranteed @secs points at > > > + * an actual EPC page. It's also possible to generate a kernel mapping > > > + * to physical EPC page by resolving PFN but using __uaccess_xx() is > > > + * simpler. > > > + */ > > > + __uaccess_begin(); > > > + ret = __ecreate(pageinfo, (void *)secs); > > > + __uaccess_end(); > > > + > > > + if (encls_faulted(ret)) { > > > + *trapnr = ENCLS_TRAPNR(ret); > > > + return -EFAULT; > > > + } > > > + > > > + /* ECREATE doesn't return an error code, it faults or succeeds. */ > > > + WARN_ON_ONCE(ret); > > > > Empty line. > > > > > + return 0; > > > +} > > > +EXPORT_SYMBOL_GPL(sgx_virt_ecreate); > > > + > > > +static int __sgx_virt_einit(void __user *sigstruct, void __user *token, > > > + void __user *secs) > > > +{ > > > + int ret; > > > + > > > + __uaccess_begin(); > > > + ret = __einit((void *)sigstruct, (void *)token, (void *)secs); > > > + __uaccess_end(); > > > > Ditto. > > > > > + return ret; > > > +} > > > + > > > +/** > > > + * sgx_virt_einit() - Run EINIT on behalf of guest > > > + * @sigstruct: Userspace pointer to SIGSTRUCT structure > > > + * @token: Userspace pointer to EINITTOKEN structure > > > + * @secs: Userspace pointer to SECS page > > > + * @lepubkeyhash: Pointer to guest's *virtual* SGX_LEPUBKEYHASH MSR > > > + * values > > > + * @trapnr: trap number injected to guest in case of EINIT error > > > + * > > > + * Run EINIT on behalf of guest after KVM traps EINIT. If SGX_LC is > > > +available > > > + * in host, SGX driver may rewrite the hardware values at wish, > > > +therefore KVM > > > + * needs to update hardware values to guest's virtual MSR values in > > > +order to > > > + * ensure EINIT is executed with expected hardware values. > > > + * > > > + * Return: > > > + * - 0: EINIT was successful. > > > + * - -EFAULT: EINIT returned error. > > > + */ > > > +int sgx_virt_einit(void __user *sigstruct, void __user *token, > > > + void __user *secs, u64 *lepubkeyhash, int *trapnr) { > > > + int ret; > > > + > > > + if (!boot_cpu_has(X86_FEATURE_SGX_LC)) { > > > + ret = __sgx_virt_einit(sigstruct, token, secs); > > > + } else { > > > + preempt_disable(); > > > + > > > + sgx_update_lepubkeyhash(lepubkeyhash); > > > + > > > + ret = __sgx_virt_einit(sigstruct, token, secs); > > > + preempt_enable(); > > > + } > > > + > > > + if (encls_faulted(ret)) { > > > + *trapnr = ENCLS_TRAPNR(ret); > > > + return -EFAULT; > > > + } > > > + > > > + return ret; > > > +} > > > +EXPORT_SYMBOL_GPL(sgx_virt_einit); > > Remove exports. Why? KVM needs to use them in later patches.
On Tue, Feb 16, 2021 at 04:55:49AM +0000, Huang, Kai wrote: > > > > On Tue, Feb 16, 2021 at 05:08:20AM +0200, Jarkko Sakkinen wrote: > > > On Sun, Feb 14, 2021 at 02:29:15AM +1300, Kai Huang wrote: > > > > From: Sean Christopherson <sean.j.christopherson@intel.com> > > > > > > > > The host kernel must intercept ECREATE to be able to impose policies > > > > on guests. When it does this, the host kernel runs ECREATE against > > > > the userspace mapping of the virtualized EPC. > > > > > > > > Provide wrappers around __ecreate() and __einit() to hide the > > > > ugliness of overloading the ENCLS return value to encode multiple > > > > error formats in a single int. KVM will trap-and-execute ECREATE > > > > and EINIT as part of SGX virtualization, and on an exception, KVM > > > > needs the trapnr so that it can inject the correct fault into the guest. > > > > > > > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > > > > Signed-off-by: Kai Huang <kai.huang@intel.com> > > > > --- > > > > v4->v5: > > > > > > > > - No code change. > > > > > > > > v3->v4: > > > > > > > > - Added one new line before last return in sgx_virt_einit(), per Jarkko. > > > > > > > > v2->v3: > > > > > > > > - Added kdoc for sgx_virt_ecreate() and sgx_virt_einit(), per Jarkko. > > > > - Changed to use CONFIG_X86_SGX_KVM. > > > > > > > > --- > > > > arch/x86/include/asm/sgx.h | 16 ++++++ > > > > arch/x86/kernel/cpu/sgx/virt.c | 94 > > > > ++++++++++++++++++++++++++++++++++ > > > > 2 files changed, 110 insertions(+) > > > > create mode 100644 arch/x86/include/asm/sgx.h > > > > > > > > diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h > > > > new file mode 100644 index 000000000000..8a3ea3e1efbe > > > > --- /dev/null > > > > +++ b/arch/x86/include/asm/sgx.h > > > > @@ -0,0 +1,16 @@ > > > > +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_X86_SGX_H > > > > +#define _ASM_X86_SGX_H > > > > + > > > > +#include <linux/types.h> > > > > + > > > > +#ifdef CONFIG_X86_SGX_KVM > > > > +struct sgx_pageinfo; > > > > + > > > > +int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs, > > > > + int *trapnr); > > > > +int sgx_virt_einit(void __user *sigstruct, void __user *token, > > > > + void __user *secs, u64 *lepubkeyhash, int *trapnr); > > > > > > s/virt/vepc/g > > No. The two are related to enclave construction (from guest), not EPC. > > For instance, what does ECREATE mean for virtual EPC? ECREATE is meaningful for enclave. > > > > > > > > +#endif > > > > + > > > > +#endif /* _ASM_X86_SGX_H */ > > > > diff --git a/arch/x86/kernel/cpu/sgx/virt.c > > > > b/arch/x86/kernel/cpu/sgx/virt.c index 47542140f8c1..016bad7cff8d > > > > 100644 > > > > --- a/arch/x86/kernel/cpu/sgx/virt.c > > > > +++ b/arch/x86/kernel/cpu/sgx/virt.c > > > > > > Rename as vepc.c. > > No. This file contains more than virtual EPC implementation, but also other staff like sgx_virt_ecreate()/sgx_virt_einit(), which are used by KVM to run ECREATE/EINIT on behalf of guest. > > > > > > > > @@ -257,3 +257,97 @@ int __init sgx_vepc_init(void) > > > > > > > > return misc_register(&sgx_vepc_dev); } > > > > + > > > > +/** > > > > + * sgx_virt_ecreate() - Run ECREATE on behalf of guest > > > > + * @pageinfo: Pointer to PAGEINFO structure > > > > + * @secs: Userspace pointer to SECS page > > > > + * @trapnr: trap number injected to guest in case of ECREATE error > > > > + * > > > > + * Run ECREATE on behalf of guest after KVM traps ECREATE for the > > > > +purpose > > > > + * of enforcing policies of guest's enclaves, and return the trap > > > > +number > > > > + * which should be injected to guest in case of any ECREATE error. > > > > + * > > > > + * Return: > > > > + * - 0: ECREATE was successful. > > > > + * - -EFAULT: ECREATE returned error. > > > > + */ > > > > +int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs, > > > > + int *trapnr) > > > > +{ > > > > + int ret; > > > > + > > > > + /* > > > > + * @secs is userspace address, and it's not guaranteed @secs points at > > > > + * an actual EPC page. It's also possible to generate a kernel mapping > > > > + * to physical EPC page by resolving PFN but using __uaccess_xx() is > > > > + * simpler. > > > > + */ > > > > + __uaccess_begin(); > > > > + ret = __ecreate(pageinfo, (void *)secs); > > > > + __uaccess_end(); > > > > + > > > > + if (encls_faulted(ret)) { > > > > + *trapnr = ENCLS_TRAPNR(ret); > > > > + return -EFAULT; > > > > + } > > > > + > > > > + /* ECREATE doesn't return an error code, it faults or succeeds. */ > > > > + WARN_ON_ONCE(ret); > > > > > > Empty line. > > > > > > > + return 0; > > > > +} > > > > +EXPORT_SYMBOL_GPL(sgx_virt_ecreate); > > > > + > > > > +static int __sgx_virt_einit(void __user *sigstruct, void __user *token, > > > > + void __user *secs) > > > > +{ > > > > + int ret; > > > > + > > > > + __uaccess_begin(); > > > > + ret = __einit((void *)sigstruct, (void *)token, (void *)secs); > > > > + __uaccess_end(); > > > > > > Ditto. > > > > > > > + return ret; > > > > +} > > > > + > > > > +/** > > > > + * sgx_virt_einit() - Run EINIT on behalf of guest > > > > + * @sigstruct: Userspace pointer to SIGSTRUCT structure > > > > + * @token: Userspace pointer to EINITTOKEN structure > > > > + * @secs: Userspace pointer to SECS page > > > > + * @lepubkeyhash: Pointer to guest's *virtual* SGX_LEPUBKEYHASH MSR > > > > + * values > > > > + * @trapnr: trap number injected to guest in case of EINIT error > > > > + * > > > > + * Run EINIT on behalf of guest after KVM traps EINIT. If SGX_LC is > > > > +available > > > > + * in host, SGX driver may rewrite the hardware values at wish, > > > > +therefore KVM > > > > + * needs to update hardware values to guest's virtual MSR values in > > > > +order to > > > > + * ensure EINIT is executed with expected hardware values. > > > > + * > > > > + * Return: > > > > + * - 0: EINIT was successful. > > > > + * - -EFAULT: EINIT returned error. > > > > + */ > > > > +int sgx_virt_einit(void __user *sigstruct, void __user *token, > > > > + void __user *secs, u64 *lepubkeyhash, int *trapnr) { > > > > + int ret; > > > > + > > > > + if (!boot_cpu_has(X86_FEATURE_SGX_LC)) { > > > > + ret = __sgx_virt_einit(sigstruct, token, secs); > > > > + } else { > > > > + preempt_disable(); > > > > + > > > > + sgx_update_lepubkeyhash(lepubkeyhash); > > > > + > > > > + ret = __sgx_virt_einit(sigstruct, token, secs); > > > > + preempt_enable(); > > > > + } > > > > + > > > > + if (encls_faulted(ret)) { > > > > + *trapnr = ENCLS_TRAPNR(ret); > > > > + return -EFAULT; > > > > + } > > > > + > > > > + return ret; > > > > +} > > > > +EXPORT_SYMBOL_GPL(sgx_virt_einit); > > > > Remove exports. > > Why? KVM needs to use them in later patches. Because they are only required for LKM's. /Jarkko
On Tue, Feb 16, 2021 at 10:33:17AM +0200, Jarkko Sakkinen wrote: > On Tue, Feb 16, 2021 at 04:55:49AM +0000, Huang, Kai wrote: > > > > > > On Tue, Feb 16, 2021 at 05:08:20AM +0200, Jarkko Sakkinen wrote: > > > > On Sun, Feb 14, 2021 at 02:29:15AM +1300, Kai Huang wrote: > > > > > From: Sean Christopherson <sean.j.christopherson@intel.com> > > > > > > > > > > The host kernel must intercept ECREATE to be able to impose policies > > > > > on guests. When it does this, the host kernel runs ECREATE against > > > > > the userspace mapping of the virtualized EPC. > > > > > > > > > > Provide wrappers around __ecreate() and __einit() to hide the > > > > > ugliness of overloading the ENCLS return value to encode multiple > > > > > error formats in a single int. KVM will trap-and-execute ECREATE > > > > > and EINIT as part of SGX virtualization, and on an exception, KVM > > > > > needs the trapnr so that it can inject the correct fault into the guest. > > > > > > > > > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > > > > > Signed-off-by: Kai Huang <kai.huang@intel.com> > > > > > --- > > > > > v4->v5: > > > > > > > > > > - No code change. > > > > > > > > > > v3->v4: > > > > > > > > > > - Added one new line before last return in sgx_virt_einit(), per Jarkko. > > > > > > > > > > v2->v3: > > > > > > > > > > - Added kdoc for sgx_virt_ecreate() and sgx_virt_einit(), per Jarkko. > > > > > - Changed to use CONFIG_X86_SGX_KVM. > > > > > > > > > > --- > > > > > arch/x86/include/asm/sgx.h | 16 ++++++ > > > > > arch/x86/kernel/cpu/sgx/virt.c | 94 > > > > > ++++++++++++++++++++++++++++++++++ > > > > > 2 files changed, 110 insertions(+) > > > > > create mode 100644 arch/x86/include/asm/sgx.h > > > > > > > > > > diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h > > > > > new file mode 100644 index 000000000000..8a3ea3e1efbe > > > > > --- /dev/null > > > > > +++ b/arch/x86/include/asm/sgx.h > > > > > @@ -0,0 +1,16 @@ > > > > > +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_X86_SGX_H > > > > > +#define _ASM_X86_SGX_H > > > > > + > > > > > +#include <linux/types.h> > > > > > + > > > > > +#ifdef CONFIG_X86_SGX_KVM > > > > > +struct sgx_pageinfo; > > > > > + > > > > > +int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs, > > > > > + int *trapnr); > > > > > +int sgx_virt_einit(void __user *sigstruct, void __user *token, > > > > > + void __user *secs, u64 *lepubkeyhash, int *trapnr); > > > > > > > > s/virt/vepc/g > > > > No. The two are related to enclave construction (from guest), not EPC. > > > > For instance, what does ECREATE mean for virtual EPC? ECREATE is meaningful for enclave. > > > > > > > > > > > +#endif > > > > > + > > > > > +#endif /* _ASM_X86_SGX_H */ > > > > > diff --git a/arch/x86/kernel/cpu/sgx/virt.c > > > > > b/arch/x86/kernel/cpu/sgx/virt.c index 47542140f8c1..016bad7cff8d > > > > > 100644 > > > > > --- a/arch/x86/kernel/cpu/sgx/virt.c > > > > > +++ b/arch/x86/kernel/cpu/sgx/virt.c > > > > > > > > Rename as vepc.c. > > > > No. This file contains more than virtual EPC implementation, but also other staff like sgx_virt_ecreate()/sgx_virt_einit(), which are used by KVM to run ECREATE/EINIT on behalf of guest. > > > > > > > > > > > @@ -257,3 +257,97 @@ int __init sgx_vepc_init(void) > > > > > > > > > > return misc_register(&sgx_vepc_dev); } > > > > > + > > > > > +/** > > > > > + * sgx_virt_ecreate() - Run ECREATE on behalf of guest > > > > > + * @pageinfo: Pointer to PAGEINFO structure > > > > > + * @secs: Userspace pointer to SECS page > > > > > + * @trapnr: trap number injected to guest in case of ECREATE error > > > > > + * > > > > > + * Run ECREATE on behalf of guest after KVM traps ECREATE for the > > > > > +purpose > > > > > + * of enforcing policies of guest's enclaves, and return the trap > > > > > +number > > > > > + * which should be injected to guest in case of any ECREATE error. > > > > > + * > > > > > + * Return: > > > > > + * - 0: ECREATE was successful. > > > > > + * - -EFAULT: ECREATE returned error. > > > > > + */ > > > > > +int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs, > > > > > + int *trapnr) > > > > > +{ > > > > > + int ret; > > > > > + > > > > > + /* > > > > > + * @secs is userspace address, and it's not guaranteed @secs points at > > > > > + * an actual EPC page. It's also possible to generate a kernel mapping > > > > > + * to physical EPC page by resolving PFN but using __uaccess_xx() is > > > > > + * simpler. > > > > > + */ > > > > > + __uaccess_begin(); > > > > > + ret = __ecreate(pageinfo, (void *)secs); > > > > > + __uaccess_end(); > > > > > + > > > > > + if (encls_faulted(ret)) { > > > > > + *trapnr = ENCLS_TRAPNR(ret); > > > > > + return -EFAULT; > > > > > + } > > > > > + > > > > > + /* ECREATE doesn't return an error code, it faults or succeeds. */ > > > > > + WARN_ON_ONCE(ret); > > > > > > > > Empty line. > > > > > > > > > + return 0; > > > > > +} > > > > > +EXPORT_SYMBOL_GPL(sgx_virt_ecreate); > > > > > + > > > > > +static int __sgx_virt_einit(void __user *sigstruct, void __user *token, > > > > > + void __user *secs) > > > > > +{ > > > > > + int ret; > > > > > + > > > > > + __uaccess_begin(); > > > > > + ret = __einit((void *)sigstruct, (void *)token, (void *)secs); > > > > > + __uaccess_end(); > > > > > > > > Ditto. > > > > > > > > > + return ret; > > > > > +} > > > > > + > > > > > +/** > > > > > + * sgx_virt_einit() - Run EINIT on behalf of guest > > > > > + * @sigstruct: Userspace pointer to SIGSTRUCT structure > > > > > + * @token: Userspace pointer to EINITTOKEN structure > > > > > + * @secs: Userspace pointer to SECS page > > > > > + * @lepubkeyhash: Pointer to guest's *virtual* SGX_LEPUBKEYHASH MSR > > > > > + * values > > > > > + * @trapnr: trap number injected to guest in case of EINIT error > > > > > + * > > > > > + * Run EINIT on behalf of guest after KVM traps EINIT. If SGX_LC is > > > > > +available > > > > > + * in host, SGX driver may rewrite the hardware values at wish, > > > > > +therefore KVM > > > > > + * needs to update hardware values to guest's virtual MSR values in > > > > > +order to > > > > > + * ensure EINIT is executed with expected hardware values. > > > > > + * > > > > > + * Return: > > > > > + * - 0: EINIT was successful. > > > > > + * - -EFAULT: EINIT returned error. > > > > > + */ > > > > > +int sgx_virt_einit(void __user *sigstruct, void __user *token, > > > > > + void __user *secs, u64 *lepubkeyhash, int *trapnr) { > > > > > + int ret; > > > > > + > > > > > + if (!boot_cpu_has(X86_FEATURE_SGX_LC)) { > > > > > + ret = __sgx_virt_einit(sigstruct, token, secs); > > > > > + } else { > > > > > + preempt_disable(); > > > > > + > > > > > + sgx_update_lepubkeyhash(lepubkeyhash); > > > > > + > > > > > + ret = __sgx_virt_einit(sigstruct, token, secs); > > > > > + preempt_enable(); > > > > > + } > > > > > + > > > > > + if (encls_faulted(ret)) { > > > > > + *trapnr = ENCLS_TRAPNR(ret); > > > > > + return -EFAULT; > > > > > + } > > > > > + > > > > > + return ret; > > > > > +} > > > > > +EXPORT_SYMBOL_GPL(sgx_virt_einit); > > > > > > Remove exports. > > > > Why? KVM needs to use them in later patches. > > Because they are only required for LKM's. I mean when LKM needs to call kernel functions. Right, KVM can be compiled as LKM. /Jarkko
> > > > > > +EXPORT_SYMBOL_GPL(sgx_virt_einit); > > > > > > > > Remove exports. > > > > > > Why? KVM needs to use them in later patches. > > > > Because they are only required for LKM's. > > I mean when LKM needs to call kernel functions. > > Right, KVM can be compiled as LKM. Just to confirm, you are OK with exposing them as symbol, since KVM (as a module) needs to use them, right?
diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h new file mode 100644 index 000000000000..8a3ea3e1efbe --- /dev/null +++ b/arch/x86/include/asm/sgx.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_SGX_H +#define _ASM_X86_SGX_H + +#include <linux/types.h> + +#ifdef CONFIG_X86_SGX_KVM +struct sgx_pageinfo; + +int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs, + int *trapnr); +int sgx_virt_einit(void __user *sigstruct, void __user *token, + void __user *secs, u64 *lepubkeyhash, int *trapnr); +#endif + +#endif /* _ASM_X86_SGX_H */ diff --git a/arch/x86/kernel/cpu/sgx/virt.c b/arch/x86/kernel/cpu/sgx/virt.c index 47542140f8c1..016bad7cff8d 100644 --- a/arch/x86/kernel/cpu/sgx/virt.c +++ b/arch/x86/kernel/cpu/sgx/virt.c @@ -257,3 +257,97 @@ int __init sgx_vepc_init(void) return misc_register(&sgx_vepc_dev); } + +/** + * sgx_virt_ecreate() - Run ECREATE on behalf of guest + * @pageinfo: Pointer to PAGEINFO structure + * @secs: Userspace pointer to SECS page + * @trapnr: trap number injected to guest in case of ECREATE error + * + * Run ECREATE on behalf of guest after KVM traps ECREATE for the purpose + * of enforcing policies of guest's enclaves, and return the trap number + * which should be injected to guest in case of any ECREATE error. + * + * Return: + * - 0: ECREATE was successful. + * - -EFAULT: ECREATE returned error. + */ +int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs, + int *trapnr) +{ + int ret; + + /* + * @secs is userspace address, and it's not guaranteed @secs points at + * an actual EPC page. It's also possible to generate a kernel mapping + * to physical EPC page by resolving PFN but using __uaccess_xx() is + * simpler. + */ + __uaccess_begin(); + ret = __ecreate(pageinfo, (void *)secs); + __uaccess_end(); + + if (encls_faulted(ret)) { + *trapnr = ENCLS_TRAPNR(ret); + return -EFAULT; + } + + /* ECREATE doesn't return an error code, it faults or succeeds. */ + WARN_ON_ONCE(ret); + return 0; +} +EXPORT_SYMBOL_GPL(sgx_virt_ecreate); + +static int __sgx_virt_einit(void __user *sigstruct, void __user *token, + void __user *secs) +{ + int ret; + + __uaccess_begin(); + ret = __einit((void *)sigstruct, (void *)token, (void *)secs); + __uaccess_end(); + return ret; +} + +/** + * sgx_virt_einit() - Run EINIT on behalf of guest + * @sigstruct: Userspace pointer to SIGSTRUCT structure + * @token: Userspace pointer to EINITTOKEN structure + * @secs: Userspace pointer to SECS page + * @lepubkeyhash: Pointer to guest's *virtual* SGX_LEPUBKEYHASH MSR + * values + * @trapnr: trap number injected to guest in case of EINIT error + * + * Run EINIT on behalf of guest after KVM traps EINIT. If SGX_LC is available + * in host, SGX driver may rewrite the hardware values at wish, therefore KVM + * needs to update hardware values to guest's virtual MSR values in order to + * ensure EINIT is executed with expected hardware values. + * + * Return: + * - 0: EINIT was successful. + * - -EFAULT: EINIT returned error. + */ +int sgx_virt_einit(void __user *sigstruct, void __user *token, + void __user *secs, u64 *lepubkeyhash, int *trapnr) +{ + int ret; + + if (!boot_cpu_has(X86_FEATURE_SGX_LC)) { + ret = __sgx_virt_einit(sigstruct, token, secs); + } else { + preempt_disable(); + + sgx_update_lepubkeyhash(lepubkeyhash); + + ret = __sgx_virt_einit(sigstruct, token, secs); + preempt_enable(); + } + + if (encls_faulted(ret)) { + *trapnr = ENCLS_TRAPNR(ret); + return -EFAULT; + } + + return ret; +} +EXPORT_SYMBOL_GPL(sgx_virt_einit);