Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Atish Patra <atishp@rivosinc.com>
To:     linux-kernel@vger.kernel.org
Cc:     Atish Patra <atishp@rivosinc.com>, Alexandre Ghiti <alex@ghiti.fr>,
        Andrew Jones <ajones@ventanamicro.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Anup Patel <anup@brainfault.org>,
        Atish Patra <atishp@atishpatra.org>,
        =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= <bjorn@rivosinc.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
        Sean Christopherson <seanjc@google.com>,
        linux-coco@lists.linux.dev, Dylan Reid <dylan@rivosinc.com>,
        abrestic@rivosinc.com, Samuel Ortiz <sameo@rivosinc.com>,
        Christoph Hellwig <hch@infradead.org>,
        Conor Dooley <conor.dooley@microchip.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Guo Ren <guoren@kernel.org>, Heiko Stuebner <heiko@sntech.de>,
        Jiri Slaby <jirislaby@kernel.org>,
        kvm-riscv@lists.infradead.org, kvm@vger.kernel.org,
        linux-mm@kvack.org, linux-riscv@lists.infradead.org,
        Mayuresh Chitale <mchitale@ventanamicro.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Rajnesh Kanwal <rkanwal@rivosinc.com>,
        Uladzislau Rezki <urezki@gmail.com>
Subject: [RFC 34/48] RISC-V: KVM: Initialize CoVE
Date:   Wed, 19 Apr 2023 15:17:02 -0700
Message-Id: <20230419221716.3603068-35-atishp@rivosinc.com>
In-Reply-To: <20230419221716.3603068-1-atishp@rivosinc.com>
References: <20230419221716.3603068-1-atishp@rivosinc.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

CoVE initialization depends on few underlying conditions that differs
from normal VMs.

1. RFENCE extension is no longer mandatory as TEEH APIs has its own set
of fence APIs.
2. SBI NACL is mandatory for TEE VMs to share memory between the host
and the TSM.

Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 arch/riscv/kvm/main.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c
index 842b78d..a059414 100644
--- a/arch/riscv/kvm/main.c
+++ b/arch/riscv/kvm/main.c
@@ -102,15 +102,12 @@ static int __init riscv_kvm_init(void)
 		return -ENODEV;
 	}
 
-	if (sbi_probe_extension(SBI_EXT_RFENCE) <= 0) {
-		kvm_info("require SBI RFENCE extension\n");
-		return -ENODEV;
-	}
-
 	rc = kvm_riscv_nacl_init();
 	if (rc && rc != -ENODEV)
 		return rc;
 
+	kvm_riscv_cove_init();
+
 	kvm_riscv_gstage_mode_detect();
 
 	kvm_riscv_gstage_vmid_detect();
@@ -121,6 +118,15 @@ static int __init riscv_kvm_init(void)
 		return rc;
 	}
 
+	/* TVM don't need RFENCE extension as hardware imsic support is mandatory for TVMs
+	 * TODO: This check should happen later if HW_ACCEL mode is not set as RFENCE
+	 * should only be mandatory in that case.
+	 */
+	if (!kvm_riscv_cove_enabled() && sbi_probe_extension(SBI_EXT_RFENCE) <= 0) {
+		kvm_info("require SBI RFENCE extension\n");
+		return -ENODEV;
+	}
+
 	kvm_info("hypervisor extension available\n");
 
 	if (kvm_riscv_nacl_available()) {
-- 
2.25.1