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AJvYcCXasqDf7JoJL1UWSwo8FDEgvRqhTyuVSpn2urElbDhN5B5fBSe1uA0ImzTiT6NzWXm5selhLQFtlyVEoZRlr2jd@lists.infradead.org X-Gm-Message-State: AOJu0YwPr1LW3LfeCv0hiMwA6jFJ1UcRywDY+Dm+o1HPfEyb98JnO+mF YO2Aeg2USnLQlP1nkZdbj838Sqy/ci/Q/F/ltDpu6Km/mIbuX3x0cPlRJxvtXtyzNQkwsptlUTc qyOkAD68xxg== X-Google-Smtp-Source: AGHT+IECH9pM1rudCKXymTwKhtnM/AU69iz4LBnNjtGpR3vZzl1lATWUss0Na2UGHQecUxyzkYn2RvfW2Hppzw== X-Received: from mostafa.c.googlers.com ([fda3:e722:ac3:cc00:28:9cb1:c0a8:333c]) (user=smostafa job=sendgmr) by 2002:a05:690c:296:b0:68d:52a1:be9 with SMTP id 00721157ae682-6e858147b16mr1078977b3.1.1729848786167; Fri, 25 Oct 2024 02:33:06 -0700 (PDT) Date: Fri, 25 Oct 2024 09:32:59 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.47.0.163.g1226f6d8fa-goog Message-ID: <20241025093259.2216093-1-smostafa@google.com> Subject: [PATCH v3] Documentation: Update the behaviour of "kvm-arm.mode" From: Mostafa Saleh To: linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: corbet@lwn.net, Mostafa Saleh , Will Deacon , Marc Zyngier X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241025_023308_847275_CA7117FA X-CRM114-Status: GOOD ( 13.12 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Commit 5053c3f0519c ("KVM: arm64: Use hVHE in pKVM by default on CPUs with VHE support") modified the behaviour of "kvm-arm.mode=protected" without the updating the kernel parameters doc. Update it to match the current implementation. Also, update required architecture version for nested virtualization as suggested by Marc. Cc: Will Deacon Cc: Marc Zyngier Signed-off-by: Mostafa Saleh --- v3: Reword as Marc suggested. v2: Update nested value also --- Documentation/admin-guide/kernel-parameters.txt | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 1518343bbe22..ed92e207e9a0 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2740,17 +2740,21 @@ nvhe: Standard nVHE-based mode, without support for protected guests. - protected: nVHE-based mode with support for guests whose - state is kept private from the host. + protected: Mode with support for guests whose state is + kept private from the host, using VHE or + nVHE depending on HW support. nested: VHE-based mode with support for nested - virtualization. Requires at least ARMv8.3 - hardware. + virtualization. Requires at least ARMv8.4 + hardware (with FEAT_NV2). Defaults to VHE/nVHE based on hardware support. Setting mode to "protected" will disable kexec and hibernation - for the host. "nested" is experimental and should be - used with extreme caution. + for the host. To force nVHE on VHE hardware, add + "arm64_sw.hvhe=0 id_aa64mmfr1.vh=0" to the + command-line. + "nested" is experimental and should be used with + extreme caution. kvm-arm.vgic_v3_group0_trap= [KVM,ARM,EARLY] Trap guest accesses to GICv3 group-0