From: Marc Zyngier <maz@kernel.org> To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: Andre Przywara <andre.przywara@arm.com>, Dave Martin <Dave.Martin@arm.com> Subject: [PATCH v2 60/94] arm64: KVM: nv: Restrict S2 RD/WR permissions to match the guest's Date: Tue, 11 Feb 2020 17:49:04 +0000 Message-ID: <20200211174938.27809-61-maz@kernel.org> (raw) In-Reply-To: <20200211174938.27809-1-maz@kernel.org> When mapping a page in a shadow stage-2, special care must be taken not to be more permissive than the guest is (writable or readable page when the guest hasn't set that permission). Signed-off-by: Marc Zyngier <maz@kernel.org> --- arch/arm/include/asm/kvm_mmu.h | 18 ++++++++++++++++++ arch/arm64/include/asm/kvm_mmu.h | 18 ++++++++++++++++++ arch/arm64/include/asm/kvm_nested.h | 10 ++++++++++ virt/kvm/arm/mmu.c | 21 ++++++++++++++++++++- 4 files changed, 66 insertions(+), 1 deletion(-) diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index 1d0d5f00f0af..be7be6583e54 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -113,6 +113,12 @@ static inline pud_t kvm_s2pud_mkexec(pud_t pud) return pud; } +static inline pud_t kvm_s2pud_revoke_read(pud_t pud) +{ + WARN_ON(1); + return pud; +} + static inline bool kvm_s2pud_exec(pud_t *pud) { WARN_ON(1); @@ -155,6 +161,18 @@ static inline pmd_t kvm_s2pmd_mkexec(pmd_t pmd) return pmd; } +static inline pte_t kvm_s2pte_revoke_read(pte_t pte) +{ + pte_val(pte) &= ~L_PTE_S2_RDONLY; + return pte; +} + +static inline pmd_t kvm_s2pmd_revoke_read(pmd_t pmd) +{ + pmd_val(pmd) &= ~L_PMD_S2_RDONLY; + return pmd; +} + static inline void kvm_set_s2pte_readonly(pte_t *pte) { pte_val(*pte) = (pte_val(*pte) & ~L_PTE_S2_RDWR) | L_PTE_S2_RDONLY; diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 9c0bf878fb3b..b390bba466e9 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -228,6 +228,24 @@ static inline pud_t kvm_s2pud_mkexec(pud_t pud) return pud; } +static inline pte_t kvm_s2pte_revoke_read(pte_t pte) +{ + pte_val(pte) &= ~PTE_S2_RDONLY; + return pte; +} + +static inline pmd_t kvm_s2pmd_revoke_read(pmd_t pmd) +{ + pmd_val(pmd) &= ~PMD_S2_RDONLY; + return pmd; +} + +static inline pud_t kvm_s2pud_revoke_read(pud_t pud) +{ + pud_val(pud) &= ~PUD_S2_RDONLY; + return pud; +} + static inline void kvm_set_s2pte_readonly(pte_t *ptep) { pteval_t old_pteval, pteval; diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h index 45c013c0c856..7cd0c5b0fec9 100644 --- a/arch/arm64/include/asm/kvm_nested.h +++ b/arch/arm64/include/asm/kvm_nested.h @@ -43,6 +43,16 @@ static inline u32 kvm_s2_trans_esr(struct kvm_s2_trans *trans) return trans->esr; } +static inline bool kvm_s2_trans_readable(struct kvm_s2_trans *trans) +{ + return trans->readable; +} + +static inline bool kvm_s2_trans_writable(struct kvm_s2_trans *trans) +{ + return trans->writable; +} + extern int kvm_walk_nested_s2(struct kvm_vcpu *vcpu, phys_addr_t gipa, struct kvm_s2_trans *result); diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index 0086b42237af..7da72c2b7f0f 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1721,7 +1721,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, unsigned long hva, unsigned long fault_status) { int ret; - bool write_fault, writable; + bool write_fault, writable, readable = true; bool exec_fault, needs_exec; unsigned long mmu_seq; phys_addr_t ipa = fault_ipa; @@ -1841,6 +1841,16 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (exec_fault && is_iomap(flags)) return -ENOEXEC; + /* + * Potentially reduce shadow S2 permissions to match the guest's own + * S2. For exec faults, we'd only reach this point if the guest + * actually allowed it (see kvm_s2_handle_perm_fault). + */ + if (kvm_is_shadow_s2_fault(vcpu)) { + writable &= kvm_s2_trans_writable(nested); + readable &= kvm_s2_trans_readable(nested); + } + spin_lock(&kvm->mmu_lock); if (mmu_notifier_retry(kvm, mmu_seq)) goto out_unlock; @@ -1886,6 +1896,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (writable) new_pud = kvm_s2pud_mkwrite(new_pud); + if (!readable) + new_pud = kvm_s2pud_revoke_read(new_pud); + if (needs_exec) new_pud = kvm_s2pud_mkexec(new_pud); @@ -1898,6 +1911,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (writable) new_pmd = kvm_s2pmd_mkwrite(new_pmd); + if (!readable) + new_pmd = kvm_s2pmd_revoke_read(new_pmd); + if (needs_exec) new_pmd = kvm_s2pmd_mkexec(new_pmd); @@ -1910,6 +1926,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, mark_page_dirty(kvm, gfn); } + if (!readable) + new_pte = kvm_s2pte_revoke_read(new_pte); + if (needs_exec) new_pte = kvm_s2pte_mkexec(new_pte); -- 2.20.1 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
next prev parent reply index Thread overview: 104+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-02-11 17:48 [PATCH v2 00/94] KVM: arm64: ARMv8.3/8.4 Nested Virtualization support Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 01/94] KVM: arm64: Move __load_guest_stage2 to kvm_mmu.h Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 02/94] arm64: Add ARM64_HAS_NESTED_VIRT cpufeature Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 03/94] KVM: arm64: nv: Introduce nested virtualization VCPU feature Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 04/94] KVM: arm64: nv: Reset VCPU to EL2 registers if VCPU nested virt is set Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 05/94] KVM: arm64: nv: Allow userspace to set PSR_MODE_EL2x Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 06/94] KVM: arm64: nv: Add EL2 system registers to vcpu context Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 07/94] KVM: arm64: nv: Reset VMPIDR_EL2 and VPIDR_EL2 to sane values Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 08/94] KVM: arm64: nv: Add nested virt VCPU primitives for vEL2 VCPU state Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 09/94] KVM: arm64: nv: Support virtual EL2 exceptions Marc Zyngier 2020-02-17 12:52 ` Mark Rutland 2020-02-17 13:41 ` Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 10/94] KVM: arm64: nv: Inject HVC exceptions to the virtual EL2 Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 11/94] KVM: arm64: nv: Handle trapped ERET from " Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 12/94] KVM: arm64: nv: Add EL2->EL1 translation helpers Marc Zyngier 2020-02-17 14:56 ` Mark Rutland 2020-02-17 17:43 ` Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 13/94] KVM: arm64: nv: Refactor vcpu_{read,write}_sys_reg Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 14/94] KVM: arm64: nv: Handle virtual EL2 registers in vcpu_read/write_sys_reg() Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 15/94] KVM: arm64: nv: Handle SPSR_EL2 specially Marc Zyngier 2020-02-17 15:04 ` Mark Rutland 2020-02-11 17:48 ` [PATCH v2 16/94] KVM: arm64: nv: Handle HCR_EL2.E2H specially Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 17/94] KVM: arm64: nv: Save/Restore vEL2 sysregs Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 18/94] KVM: arm64: nv: Emulate PSTATE.M for a guest hypervisor Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 19/94] KVM: arm64: nv: Trap EL1 VM register accesses in virtual EL2 Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 20/94] KVM: arm64: nv: Trap SPSR_EL1, ELR_EL1 and VBAR_EL1 from " Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 21/94] KVM: arm64: nv: Trap CPACR_EL1 access in " Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 22/94] KVM: arm64: nv: Handle PSCI call via smc from the guest Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 23/94] KVM: arm64: nv: Respect virtual HCR_EL2.TWX setting Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 24/94] KVM: arm64: nv: Respect virtual CPTR_EL2.{TFP, FPEN} settings Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 25/94] KVM: arm64: nv: Respect the virtual HCR_EL2.NV bit setting Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 26/94] KVM: arm64: nv: Respect virtual HCR_EL2.TVM and TRVM settings Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 27/94] KVM: arm64: nv: Respect the virtual HCR_EL2.NV1 bit setting Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 28/94] KVM: arm64: nv: Emulate EL12 register accesses from the virtual EL2 Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 29/94] KVM: arm64: nv: Forward debug traps to the nested guest Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 30/94] KVM: arm64: nv: Configure HCR_EL2 for nested virtualization Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 31/94] KVM: arm64: nv: Only toggle cache for virtual EL2 when SCTLR_EL2 changes Marc Zyngier 2020-02-17 15:13 ` Mark Rutland 2020-02-11 17:48 ` [PATCH v2 32/94] KVM: arm64: nv: Filter out unsupported features from ID regs Marc Zyngier 2020-02-17 15:17 ` Mark Rutland 2020-02-11 17:48 ` [PATCH v2 33/94] KVM: arm64: nv: Hide RAS from nested guests Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 34/94] KVM: arm64: nv: Use ARMv8.5-GTG to advertise supported Stage-2 page sizes Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 35/94] KVM: arm64: Check advertised Stage-2 page size capability Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 36/94] KVM: arm/arm64: nv: Factor out stage 2 page table data from struct kvm Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 37/94] KVM: arm64: nv: Support multiple nested Stage-2 mmu structures Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 38/94] KVM: arm64: nv: Implement nested Stage-2 page table walk logic Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 39/94] KVM: arm64: nv: Handle shadow stage 2 page faults Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 40/94] KVM: arm64: nv: Unmap/flush shadow stage 2 page tables Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 41/94] KVM: arm64: nv: Move last_vcpu_ran to be per s2 mmu Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 42/94] KVM: arm64: nv: Introduce sys_reg_desc.forward_trap Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 43/94] KVM: arm64: nv: Set a handler for the system instruction traps Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 44/94] KVM: arm64: nv: Trap and emulate AT instructions from virtual EL2 Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 45/94] KVM: arm64: nv: Trap and emulate TLBI " Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 46/94] KVM: arm64: nv: Fold guest's HCR_EL2 configuration into the host's Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 47/94] KVM: arm64: nv: Handle traps for timer _EL02 and _EL2 sysregs accessors Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 48/94] KVM: arm64: nv: arch_timer: Support hyp timer emulation Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 49/94] KVM: arm64: nv: Propagate CNTVOFF_EL2 to the virtual EL1 timer Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 50/94] KVM: arm64: nv: Load timer before the GIC Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 51/94] KVM: arm64: nv: vgic-v3: Take cpu_if pointer directly instead of vcpu Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 52/94] KVM: arm64: nv: Nested GICv3 Support Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 53/94] KVM: arm64: nv: vgic: Emulate the HW bit in software Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 54/94] KVM: arm64: nv: vgic: Allow userland to set VGIC maintenance IRQ Marc Zyngier 2020-02-11 17:48 ` [PATCH v2 55/94] KVM: arm64: nv: Implement maintenance interrupt forwarding Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 56/94] KVM: arm64: nv: Add nested GICv3 tracepoints Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 57/94] arm64: KVM: nv: Add handling of EL2-specific timer registers Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 58/94] arm64: KVM: nv: Honor SCTLR_EL2.SPAN on entering vEL2 Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 59/94] arm64: KVM: nv: Handle SCTLR_EL2 RES0/RES1 bits Marc Zyngier 2020-02-11 17:49 ` Marc Zyngier [this message] 2020-02-11 17:49 ` [PATCH v2 61/94] arm64: KVM: nv: Allow userspace to request KVM_ARM_VCPU_NESTED_VIRT Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 62/94] arm64: Detect the ARMv8.4 TTL feature Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 63/94] arm64: KVM: nv: Add handling of ARMv8.4-TTL TLB invalidation Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 64/94] arm64: KVM: nv: Invalidate TLBs based on shadow S2 TTL-like information Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 65/94] arm64: KVM: nv: Tag shadow S2 entries with nested level Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 66/94] arm64: Add SW reserved PTE/PMD bits Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 67/94] arm64: Add level-hinted TLB invalidation helper Marc Zyngier 2020-03-25 10:38 ` Zhenyu Ye 2020-03-25 11:28 ` Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 68/94] arm64: KVM: Add a level hint to __kvm_tlb_flush_vmid_ipa Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 69/94] arm64: KVM: Use TTL hint in when invalidating stage-2 translations Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 70/94] arm64: KVM: nv: Add include containing the VNCR_EL2 offsets Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 71/94] KVM: arm64: Introduce accessor for ctxt->sys_reg Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 72/94] KVM: arm64: sysreg: Use ctxt_sys_reg() instead of raw sys_regs access Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 73/94] KVM: arm64: sve: Use __vcpu_sys_reg() " Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 74/94] KVM: arm64: pauth: Use ctxt_sys_reg() " Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 75/94] KVM: arm64: debug: " Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 76/94] KVM: arm64: Add missing reset handlers for PMU emulation Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 77/94] KVM: arm64: nv: Move sysreg reset check to boot time Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 78/94] KVM: arm64: Map VNCR-capable registers to a separate page Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 79/94] KVM: arm64: nv: Move nested vgic state into the sysreg file Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 80/94] KVM: arm64: Use accessors for timer ctl/cval/offset Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 81/94] KVM: arm64: Add VNCR-capable timer accessors for arm64 Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 82/94] KVM: arm64: Make struct kvm_regs userspace-only Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 83/94] KVM: arm64: VNCR-ize ELR_EL1 Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 84/94] KVM: arm64: VNCR-ize SP_EL1 Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 85/94] KVM: arm64: Disintegrate SPSR array Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 86/94] KVM: arm64: aarch32: Use __vcpu_sys_reg() instead of raw sys_regs access Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 87/94] KVM: arm64: VNCR-ize SPSR_EL1 Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 88/94] KVM: arm64: Add ARMv8.4 Enhanced Nested Virt cpufeature Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 89/94] KVM: arm64: nv: Synchronize PSTATE early on exit Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 90/94] KVM: arm64: nv: Sync nested timer state with ARMv8.4 Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 91/94] KVM: arm64: nv: Allocate VNCR page when required Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 92/94] KVM: arm64: nv: Enable ARMv8.4-NV support Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 93/94] KVM: arm64: nv: Fast-track 'InHost' exception returns Marc Zyngier 2020-02-11 17:49 ` [PATCH v2 94/94] KVM: arm64: nv: Fast-track EL1 TLBIs for VHE guests Marc Zyngier
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