Documentation: Update the behaviour of "kvm-arm.mode"

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 <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Signed-off-by: Mostafa Saleh <smostafa@google.com>
Link: https://lore.kernel.org/r/20241025093259.2216093-1-smostafa@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 3872bc6ec49d63772755504966ae70113f24a1db..7c870883af8e39ef8509005fb13ab2df1761cf22 100644 (file)
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2748,17 +2748,21 @@
                        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