linux-kernel - [PATCH v2 15/25] KVM: x86: Export kvm_mmu_gva_to_gpa

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue,  9 Mar 2021 14:40:22 +1300
From:   Kai Huang <kai.huang@...el.com>
To:     kvm@...r.kernel.org, x86@...nel.org, linux-sgx@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, seanjc@...gle.com, jarkko@...nel.org,
        luto@...nel.org, dave.hansen@...el.com, rick.p.edgecombe@...el.com,
        haitao.huang@...el.com, pbonzini@...hat.com, bp@...en8.de,
        tglx@...utronix.de, mingo@...hat.com, hpa@...or.com,
        jmattson@...gle.com, joro@...tes.org, vkuznets@...hat.com,
        wanpengli@...cent.com, Kai Huang <kai.huang@...el.com>
Subject: [PATCH v2 15/25] KVM: x86: Export kvm_mmu_gva_to_gpa_{read,write}() for SGX (VMX)

From: Sean Christopherson <sean.j.christopherson@...el.com>

Export the gva_to_gpa() helpers for use by SGX virtualization when
executing ENCLS[ECREATE] and ENCLS[EINIT] on behalf of the guest.
To execute ECREATE and EINIT, KVM must obtain the GPA of the target
Secure Enclave Control Structure (SECS) in order to get its
corresponding HVA.

Because the SECS must reside in the Enclave Page Cache (EPC), copying
the SECS's data to a host-controlled buffer via existing exported
helpers is not a viable option as the EPC is not readable or writable
by the kernel.

SGX virtualization will also use gva_to_gpa() to obtain HVAs for
non-EPC pages in order to pass user pointers directly to ECREATE and
EINIT, which avoids having to copy pages worth of data into the kernel.

Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
Acked-by: Jarkko Sakkinen <jarkko@...nel.org>
Signed-off-by: Kai Huang <kai.huang@...el.com>
---
 arch/x86/kvm/x86.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2a20ce60152e..5233e3ad69ee 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5959,6 +5959,7 @@ gpa_t kvm_mmu_gva_to_gpa_read(struct kvm_vcpu *vcpu, gva_t gva,
 	u32 access = (static_call(kvm_x86_get_cpl)(vcpu) == 3) ? PFERR_USER_MASK : 0;
 	return vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, access, exception);
 }
+EXPORT_SYMBOL_GPL(kvm_mmu_gva_to_gpa_read);
 
  gpa_t kvm_mmu_gva_to_gpa_fetch(struct kvm_vcpu *vcpu, gva_t gva,
 				struct x86_exception *exception)
@@ -5975,6 +5976,7 @@ gpa_t kvm_mmu_gva_to_gpa_write(struct kvm_vcpu *vcpu, gva_t gva,
 	access |= PFERR_WRITE_MASK;
 	return vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, access, exception);
 }
+EXPORT_SYMBOL_GPL(kvm_mmu_gva_to_gpa_write);
 
 /* uses this to access any guest's mapped memory without checking CPL */
 gpa_t kvm_mmu_gva_to_gpa_system(struct kvm_vcpu *vcpu, gva_t gva,
-- 
2.29.2