linux-kernel - [PATCH 1/2] LoongArch: KVM: Add sign extension with kernel MMIO read emulation

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 for Android: free password hash cracker in your pocket

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

Message-Id: <20250819121725.2423941-2-maobibo@loongson.cn>
Date: Tue, 19 Aug 2025 20:17:24 +0800
From: Bibo Mao <maobibo@...ngson.cn>
To: Huacai Chen <chenhuacai@...nel.org>,
	Xianglai Li <lixianglai@...ngson.cn>
Cc: kvm@...r.kernel.org,
	loongarch@...ts.linux.dev,
	linux-kernel@...r.kernel.org
Subject: [PATCH 1/2] LoongArch: KVM: Add sign extension with kernel MMIO read emulation

Function kvm_complete_mmio_read() is to add sign extension with MMIO
read emulation, it is used in user space MMIO read return now. Also
it can be used in kernel MMIO read emulation.

Signed-off-by: Bibo Mao <maobibo@...ngson.cn>
---
 arch/loongarch/kvm/exit.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c
index 2ce41f93b2a4..6fee1b8c35eb 100644
--- a/arch/loongarch/kvm/exit.c
+++ b/arch/loongarch/kvm/exit.c
@@ -468,6 +468,9 @@ int kvm_emu_mmio_read(struct kvm_vcpu *vcpu, larch_inst inst)
 	if (ret == EMULATE_DO_MMIO) {
 		trace_kvm_mmio(KVM_TRACE_MMIO_READ, run->mmio.len, run->mmio.phys_addr, NULL);
 
+		/* Set for kvm_complete_mmio_read() use */
+		vcpu->arch.io_gpr = rd;
+
 		/*
 		 * If mmio device such as PCH-PIC is emulated in KVM,
 		 * it need not return to user space to handle the mmio
@@ -475,16 +478,15 @@ int kvm_emu_mmio_read(struct kvm_vcpu *vcpu, larch_inst inst)
 		 */
 		idx = srcu_read_lock(&vcpu->kvm->srcu);
 		ret = kvm_io_bus_read(vcpu, KVM_MMIO_BUS, vcpu->arch.badv,
-				      run->mmio.len, &vcpu->arch.gprs[rd]);
+				      run->mmio.len, run->mmio.data);
 		srcu_read_unlock(&vcpu->kvm->srcu, idx);
 		if (!ret) {
+			kvm_complete_mmio_read(vcpu, run);
 			update_pc(&vcpu->arch);
 			vcpu->mmio_needed = 0;
 			return EMULATE_DONE;
 		}
 
-		/* Set for kvm_complete_mmio_read() use */
-		vcpu->arch.io_gpr = rd;
 		run->mmio.is_write = 0;
 		vcpu->mmio_is_write = 0;
 		return EMULATE_DO_MMIO;
-- 
2.39.3