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charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: D4FF1100016 X-Rspam-User: X-Stat-Signature: fx3u4g69z6cs37qree3huagt46wcigup X-HE-Tag: 1768398383-812752 X-HE-Meta: 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 p/pbBI6q 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Patrick Roy =0A= =0A= Support for GUEST_MEMFD_FLAG_NO_DIRECT_MAP on arm64 depends on 1) direct=0A= map manipulations at 4k granularity being possible, and 2) FEAT_S2FWB.=0A= =0A= 1) is met whenever the direct map is set up at 4k granularity (e.g. not=0A= with huge/gigantic pages) at boottime, as due to ARM's=0A= break-before-make semantics, breaking huge mappings into 4k mappings in=0A= the direct map is not possible (BBM would require temporary invalidation=0A= of the entire huge mapping, even if only a 4k subrange should be zapped,=0A= which will probably crash the kernel). However, the current default for=0A= rodata_full is true, which forces a 4k direct map.=0A= =0A= 2) is required to allow KVM to elide cache coherency operations when=0A= installing stage 2 page tables, which require the direct map to be=0A= entry for the newly mapped memory to be present (which it will not be,=0A= as guest_memfd would have removed direct map entries in=0A= kvm_gmem_get_pfn()).=0A= =0A= Cc: Will Deacon =0A= Signed-off-by: Patrick Roy =0A= Signed-off-by: Nikita Kalyazin =0A= ---=0A= arch/arm64/include/asm/kvm_host.h | 13 +++++++++++++=0A= 1 file changed, 13 insertions(+)=0A= =0A= diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm= _host.h=0A= index ac7f970c7883..d431ca7d4fc9 100644=0A= --- a/arch/arm64/include/asm/kvm_host.h=0A= +++ b/arch/arm64/include/asm/kvm_host.h=0A= @@ -19,6 +19,7 @@=0A= #include =0A= #include =0A= #include =0A= +#include =0A= #include =0A= #include =0A= #include =0A= @@ -1654,5 +1655,17 @@ static __always_inline enum fgt_group_id __fgt_reg_t= o_group_id(enum vcpu_sysreg=0A= \=0A= p; \=0A= })=0A= +#ifdef CONFIG_KVM_GUEST_MEMFD=0A= +static inline bool kvm_arch_gmem_supports_no_direct_map(void)=0A= +{=0A= + /*=0A= + * Without FWB, direct map access is needed in kvm_pgtable_stage2_map(),= =0A= + * as it calls dcache_clean_inval_poc().=0A= + */=0A= + return can_set_direct_map() && cpus_have_final_cap(ARM64_HAS_STAGE2_FWB);= =0A= +}=0A= +#define kvm_arch_gmem_supports_no_direct_map kvm_arch_gmem_supports_no_dir= ect_map=0A= +#endif /* CONFIG_KVM_GUEST_MEMFD */=0A= +=0A= =0A= #endif /* __ARM64_KVM_HOST_H__ */=0A= -- =0A= 2.50.1=0A= =0A=