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| author |   Vitaly Kuznetsov <vkuznets@redhat.com> | 2021-01-28 13:01:31 -0500 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2021-02-09 08:17:08 -0500 |
| commit | 4fc096a99e01dd06dc55bef76ade7f8d76653245 (patch) | |
| tree | d02ee91f59c3b01892a974066c6ee3f962dcee89 /arch/powerpc/include/asm/kvm_host.h | |
| parent | selftests: kvm: Raise the default timeout to 120 seconds (diff) | |
| download | wireguard-linux-4fc096a99e01dd06dc55bef76ade7f8d76653245.tar.xz wireguard-linux-4fc096a99e01dd06dc55bef76ade7f8d76653245.zip | |
KVM: Raise the maximum number of user memslots
Current KVM_USER_MEM_SLOTS limits are arch specific (512 on Power, 509 on x86,
32 on s390, 16 on MIPS) but they don't really need to be. Memory slots are
allocated dynamically in KVM when added so the only real limitation is
'id_to_index' array which is 'short'. We don't have any other
KVM_MEM_SLOTS_NUM/KVM_USER_MEM_SLOTS-sized statically defined structures.
Low KVM_USER_MEM_SLOTS can be a limiting factor for some configurations.
In particular, when QEMU tries to start a Windows guest with Hyper-V SynIC
enabled and e.g. 256 vCPUs the limit is hit as SynIC requires two pages per
vCPU and the guest is free to pick any GFN for each of them, this fragments
memslots as QEMU wants to have a separate memslot for each of these pages
(which are supposed to act as 'overlay' pages).
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210127175731.2020089-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/powerpc/include/asm/kvm_host.h')
| -rw-r--r-- | arch/powerpc/include/asm/kvm_host.h | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index d67a470e95a3..2b9b6855ec86 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -28,7 +28,6 @@ #define KVM_MAX_VCPUS NR_CPUS #define KVM_MAX_VCORES NR_CPUS -#define KVM_USER_MEM_SLOTS 512 #include <asm/cputhreads.h> |