From patchwork Tue Dec 5 16:48:13 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 750565 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D296C4174B; Tue, 5 Dec 2023 16:52:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="YJSZMdbp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9BFC9C433CB; Tue, 5 Dec 2023 16:51:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1701795120; bh=lmwKeOVCrjRhM2ZiQavbt1CMHDfnXPXsSHRFSbvASgY=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=YJSZMdbpf3cGa4tsWeH9aLbOKueHUle3KTRngPCazZc9OXihPMYYuwFlE1poD6oD7 Uj5bHtm78+hi6adRlUGbZFGybyDcNO2Rj8ps7+qkikfak01r7DOMMXmrAd/crYprLh tMcc9JfQJJFeiSitwRxJJ58PaEAWv/lOiJUGksPGKQOuYXJbh3S4T0OrmMDoo30JP+ lUk6BDeEBYUpBR/RxjRxM2B5LrUpW0hfLCrcCm6hiu0MoDnadB9eK9mvzSEtbrKI9+ qiCDM3dK4BJeFcYBWoM50H+VcBqypA+Gylgv45v+f0kcyznWC3KK88gbLKjj6phktB UKVYLX5HY7Omw== From: Mark Brown Date: Tue, 05 Dec 2023 16:48:13 +0000 Subject: [PATCH v3 15/21] KVM: arm64: Support FEAT_FPMR for guests Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20231205-arm64-2023-dpisa-v3-15-dbcbcd867a7f@kernel.org> References: <20231205-arm64-2023-dpisa-v3-0-dbcbcd867a7f@kernel.org> In-Reply-To: <20231205-arm64-2023-dpisa-v3-0-dbcbcd867a7f@kernel.org> To: Catalin Marinas , Will Deacon , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Jonathan Corbet , Shuah Khan Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, Mark Brown X-Mailer: b4 0.13-dev-5c066 X-Developer-Signature: v=1; a=openpgp-sha256; l=7570; i=broonie@kernel.org; h=from:subject:message-id; bh=lmwKeOVCrjRhM2ZiQavbt1CMHDfnXPXsSHRFSbvASgY=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBlb1T0nCUmgcwLGhObXw5qT8gb8CkHf3xXJHZdmuvi YdeDGASJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZW9U9AAKCRAk1otyXVSH0J4TB/ sEuL7+vzjMoZMxGkeCRGAhhzMAPZEdxZuFTwTzlXkwpnbE7syjfqzXFrt3ZhGMZzBzLGLfSHi5WHk2 9+VtiIEv8gGzSg7UZmI7jR/zHcC3IvdLTVJHMwekEbLqk0XcSbjZWTOEfrTL8YpG4oo5s9OjP+J50A 4EnroItGRiX3QOfBOM6p6dmiQJjA7YeSr4ouSFS289yqSTKeIZGTJLXtfIJmL0uuLIgtPm1Xw+1fZC tUbb0MyqVONGtRboE2JIYIfXgZ9yGKLL2Se/omh2bJ/0ilFpTq+gSTLHBz8bt28Hm1hNQZtQqJ23fy Bj/p7PLoZEP6fxCFIMjF9i+EwNZTGX X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB FEAT_FPMR introduces a new system register FPMR which allows configuration of floating point behaviour, currently for FP8 specific features. Allow use of this in guests, disabling the trap while guests are running and saving and restoring the value along with the rest of the floating point state. Since FPMR is stored immediately after the main floating point state we share it with the hypervisor by adjusting the size of the shared region. Access to FPMR is covered by both a register specific trap HCRX_EL2.EnFPM and the overall floating point access trap so we just unconditionally enable the FPMR specific trap and rely on the floating point access trap to detect guest floating point usage. Signed-off-by: Mark Brown --- arch/arm64/include/asm/kvm_arm.h | 2 +- arch/arm64/include/asm/kvm_host.h | 4 +++- arch/arm64/kvm/emulate-nested.c | 9 +++++++++ arch/arm64/kvm/fpsimd.c | 20 +++++++++++++++++--- arch/arm64/kvm/hyp/include/hyp/switch.h | 7 ++++++- arch/arm64/kvm/sys_regs.c | 11 +++++++++++ 6 files changed, 47 insertions(+), 6 deletions(-) diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 9f9239d86900..95f3b44e7c3a 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -103,7 +103,7 @@ #define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H) #define HCRX_GUEST_FLAGS \ - (HCRX_EL2_SMPME | HCRX_EL2_TCR2En | \ + (HCRX_EL2_SMPME | HCRX_EL2_TCR2En | HCRX_EL2_EnFPM | \ (cpus_have_final_cap(ARM64_HAS_MOPS) ? (HCRX_EL2_MSCEn | HCRX_EL2_MCE2) : 0)) #define HCRX_HOST_FLAGS (HCRX_EL2_MSCEn | HCRX_EL2_TCR2En | HCRX_EL2_EnFPM) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index f8d98985a39c..9885adff06fa 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -391,6 +391,8 @@ enum vcpu_sysreg { CNTP_CVAL_EL0, CNTP_CTL_EL0, + FPMR, + /* Memory Tagging Extension registers */ RGSR_EL1, /* Random Allocation Tag Seed Register */ GCR_EL1, /* Tag Control Register */ @@ -517,7 +519,6 @@ struct kvm_vcpu_arch { enum fp_type fp_type; unsigned int sve_max_vl; u64 svcr; - u64 fpmr; /* Stage 2 paging state used by the hardware on next switch */ struct kvm_s2_mmu *hw_mmu; @@ -576,6 +577,7 @@ struct kvm_vcpu_arch { struct kvm_guest_debug_arch external_debug_state; struct user_fpsimd_state *host_fpsimd_state; /* hyp VA */ + u64 *host_fpmr; /* hyp VA */ struct task_struct *parent_task; struct { diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c index 06185216a297..802e5cde696f 100644 --- a/arch/arm64/kvm/emulate-nested.c +++ b/arch/arm64/kvm/emulate-nested.c @@ -67,6 +67,8 @@ enum cgt_group_id { CGT_HCR_TTLBIS, CGT_HCR_TTLBOS, + CGT_HCRX_EnFPM, + CGT_MDCR_TPMCR, CGT_MDCR_TPM, CGT_MDCR_TDE, @@ -279,6 +281,12 @@ static const struct trap_bits coarse_trap_bits[] = { .mask = HCR_TTLBOS, .behaviour = BEHAVE_FORWARD_ANY, }, + [CGT_HCRX_EnFPM] = { + .index = HCRX_EL2, + .value = HCRX_EL2_EnFPM, + .mask = HCRX_EL2_EnFPM, + .behaviour = BEHAVE_FORWARD_ANY, + }, [CGT_MDCR_TPMCR] = { .index = MDCR_EL2, .value = MDCR_EL2_TPMCR, @@ -478,6 +486,7 @@ static const struct encoding_to_trap_config encoding_to_cgt[] __initconst = { SR_TRAP(SYS_AIDR_EL1, CGT_HCR_TID1), SR_TRAP(SYS_SMIDR_EL1, CGT_HCR_TID1), SR_TRAP(SYS_CTR_EL0, CGT_HCR_TID2), + SR_TRAP(SYS_FPMR, CGT_HCRX_EnFPM), SR_TRAP(SYS_CCSIDR_EL1, CGT_HCR_TID2_TID4), SR_TRAP(SYS_CCSIDR2_EL1, CGT_HCR_TID2_TID4), SR_TRAP(SYS_CLIDR_EL1, CGT_HCR_TID2_TID4), diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index e3e611e30e91..dee078625d0d 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -14,6 +14,16 @@ #include #include +static void *fpsimd_share_end(struct user_fpsimd_state *fpsimd) +{ + void *share_end = fpsimd + 1; + + if (cpus_have_final_cap(ARM64_HAS_FPMR)) + share_end += sizeof(u64); + + return share_end; +} + void kvm_vcpu_unshare_task_fp(struct kvm_vcpu *vcpu) { struct task_struct *p = vcpu->arch.parent_task; @@ -23,7 +33,7 @@ void kvm_vcpu_unshare_task_fp(struct kvm_vcpu *vcpu) return; fpsimd = &p->thread.uw.fpsimd_state; - kvm_unshare_hyp(fpsimd, fpsimd + 1); + kvm_unshare_hyp(fpsimd, fpsimd_share_end(fpsimd)); put_task_struct(p); } @@ -45,11 +55,15 @@ int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu) kvm_vcpu_unshare_task_fp(vcpu); /* Make sure the host task fpsimd state is visible to hyp: */ - ret = kvm_share_hyp(fpsimd, fpsimd + 1); + ret = kvm_share_hyp(fpsimd, fpsimd_share_end(fpsimd)); if (ret) return ret; vcpu->arch.host_fpsimd_state = kern_hyp_va(fpsimd); + if (cpus_have_final_cap(ARM64_HAS_FPMR)) { + WARN_ON_ONCE(¤t->thread.fpmr + 1 != fpsimd_share_end(fpsimd)); + vcpu->arch.host_fpmr = kern_hyp_va(¤t->thread.fpmr); + } /* * We need to keep current's task_struct pinned until its data has been @@ -153,7 +167,7 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu) fp_state.sve_vl = vcpu->arch.sve_max_vl; fp_state.sme_state = NULL; fp_state.svcr = &vcpu->arch.svcr; - fp_state.fpmr = &vcpu->arch.fpmr; + fp_state.fpmr = &__vcpu_sys_reg(vcpu, FPMR); fp_state.fp_type = &vcpu->arch.fp_type; if (vcpu_has_sve(vcpu)) diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index f99d8af0b9af..a51b21a2e26f 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -339,10 +339,15 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) isb(); /* Write out the host state if it's in the registers */ - if (vcpu->arch.fp_state == FP_STATE_HOST_OWNED) + if (vcpu->arch.fp_state == FP_STATE_HOST_OWNED) { __fpsimd_save_state(vcpu->arch.host_fpsimd_state); + if (cpus_have_final_cap(ARM64_HAS_FPMR)) + *vcpu->arch.host_fpmr = read_sysreg_s(SYS_FPMR); + } /* Restore the guest state */ + if (cpus_have_final_cap(ARM64_HAS_FPMR)) + write_sysreg_s(__vcpu_sys_reg(vcpu, FPMR), SYS_FPMR); if (sve_guest) __hyp_sve_restore_guest(vcpu); else diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index b843da5e4bb9..0789fb632623 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1914,6 +1914,15 @@ static unsigned int hidden_user_visibility(const struct kvm_vcpu *vcpu, .visibility = hidden_user_visibility, \ } +static unsigned int fpmr_visibility(const struct kvm_vcpu *vcpu, + const struct sys_reg_desc *rd) +{ + if (cpus_have_final_cap(ARM64_HAS_FPMR)) + return 0; + + return REG_HIDDEN; +} + /* * Since reset() callback and field val are not used for idregs, they will be * used for specific purposes for idregs. @@ -2310,6 +2319,8 @@ static const struct sys_reg_desc sys_reg_descs[] = { { SYS_DESC(SYS_CSSELR_EL1), access_csselr, reset_unknown, CSSELR_EL1 }, { SYS_DESC(SYS_CTR_EL0), access_ctr }, { SYS_DESC(SYS_SVCR), undef_access }, + { SYS_DESC(SYS_FPMR), access_rw, reset_unknown, FPMR, + .visibility = fpmr_visibility }, { PMU_SYS_REG(PMCR_EL0), .access = access_pmcr, .reset = reset_pmcr, .reg = PMCR_EL0, .get_user = get_pmcr, .set_user = set_pmcr },