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From: Sean Christopherson <seanjc@google.com>
To: Sean Christopherson <seanjc@google.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	 Vitaly Kuznetsov <vkuznets@redhat.com>,
	David Woodhouse <dwmw2@infradead.org>,
	Paul Durrant <paul@xen.org>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	 Yosry Ahmed <yosry@kernel.org>
Subject: [PATCH 04/11] KVM: VMX: Read 32-bit GPR values for ENCLS instructions outside of 64-bit mode
Date: Thu,  9 Apr 2026 16:56:15 -0700	[thread overview]
Message-ID: <20260409235622.2052730-5-seanjc@google.com> (raw)
In-Reply-To: <20260409235622.2052730-1-seanjc@google.com>

When getting register values for ENCLS emulation, use kvm_register_read()
instead of kvm_<reg>_read() so that bits 63:32 of the register are dropped
if the guest is in 32-bit mode.

Note, the misleading/surprising behavior of kvm_<reg>_read() being "raw"
variants under the hood will be addressed once all non-benign bugs are
fixed.

Fixes: 70210c044b4e ("KVM: VMX: Add SGX ENCLS[ECREATE] handler to enforce CPUID restrictions")
Fixes: b6f084ca5538 ("KVM: VMX: Add ENCLS[EINIT] handler to support SGX Launch Control (LC)")
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/vmx/sgx.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/vmx/sgx.c b/arch/x86/kvm/vmx/sgx.c
index df1d0cf76947..4c61fc33f764 100644
--- a/arch/x86/kvm/vmx/sgx.c
+++ b/arch/x86/kvm/vmx/sgx.c
@@ -225,8 +225,8 @@ static int handle_encls_ecreate(struct kvm_vcpu *vcpu)
 	struct x86_exception ex;
 	int r;
 
-	if (sgx_get_encls_gva(vcpu, kvm_rbx_read(vcpu), 32, 32, &pageinfo_gva) ||
-	    sgx_get_encls_gva(vcpu, kvm_rcx_read(vcpu), 4096, 4096, &secs_gva))
+	if (sgx_get_encls_gva(vcpu, kvm_register_read(vcpu, VCPU_REGS_RBX), 32, 32, &pageinfo_gva) ||
+	    sgx_get_encls_gva(vcpu, kvm_register_read(vcpu, VCPU_REGS_RCX), 4096, 4096, &secs_gva))
 		return 1;
 
 	/*
@@ -302,9 +302,9 @@ static int handle_encls_einit(struct kvm_vcpu *vcpu)
 	gpa_t sig_gpa, secs_gpa, token_gpa;
 	int ret, trapnr;
 
-	if (sgx_get_encls_gva(vcpu, kvm_rbx_read(vcpu), 1808, 4096, &sig_gva) ||
-	    sgx_get_encls_gva(vcpu, kvm_rcx_read(vcpu), 4096, 4096, &secs_gva) ||
-	    sgx_get_encls_gva(vcpu, kvm_rdx_read(vcpu), 304, 512, &token_gva))
+	if (sgx_get_encls_gva(vcpu, kvm_register_read(vcpu, VCPU_REGS_RBX), 1808, 4096, &sig_gva) ||
+	    sgx_get_encls_gva(vcpu, kvm_register_read(vcpu, VCPU_REGS_RCX), 4096, 4096, &secs_gva) ||
+	    sgx_get_encls_gva(vcpu, kvm_register_read(vcpu, VCPU_REGS_RDX), 304, 512, &token_gva))
 		return 1;
 
 	/*
-- 
2.53.0.1213.gd9a14994de-goog


  parent reply	other threads:[~2026-04-09 23:56 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-09 23:56 [PATCH 00/11] KVM: x86: Clean up kvm_<reg>_{read,write}() mess Sean Christopherson
2026-04-09 23:56 ` [PATCH 01/11] KVM: SVM: Truncate INVLPGA address in compatibility mode Sean Christopherson
2026-04-09 23:56 ` [PATCH 02/11] KVM: x86/xen: Bug the VM if 32-bit KVM observes a 64-bit mode hypercall Sean Christopherson
2026-04-09 23:56 ` [PATCH 03/11] KVM: x86/xen: Don't truncate RAX when handling hypercall from protected guest Sean Christopherson
2026-04-09 23:56 ` Sean Christopherson [this message]
2026-04-09 23:56 ` [PATCH 05/11] KVM: x86: Trace hypercall register *after* truncating values for 32-bit Sean Christopherson
2026-04-09 23:56 ` [PATCH 06/11] KVM: x86: Move kvm_<reg>_{read,write}() definitions to x86.h Sean Christopherson
2026-04-09 23:56 ` [PATCH 07/11] KVM: x86: Add mode-aware versions of kvm_<reg>_{read,write}() helpers Sean Christopherson
2026-04-09 23:56 ` [PATCH 08/11] KVM: x86: Drop non-raw kvm_<reg>_write() helpers Sean Christopherson
2026-04-09 23:56 ` [PATCH 09/11] KVM: nSVM: Use kvm_rax_read() now that it's mode-aware Sean Christopherson
2026-04-09 23:56 ` [PATCH 10/11] Revert "KVM: VMX: Read 32-bit GPR values for ENCLS instructions outside of 64-bit mode" Sean Christopherson
2026-04-09 23:56 ` [PATCH 11/11] KVM: x86: Harden is_64_bit_hypercall() against bugs on 32-bit kernels Sean Christopherson

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