On 27-01-2023 04:59 pm, Steven Price wrote:
The RMM owns the stage 2 page tables for a realm, and KVM must request that the RMM creates/destroys entries as necessary. The physical pages to store the page tables are delegated to the realm as required, and can be undelegated when no longer used. Signed-off-by: Steven Price <steven.price@xxxxxxx> --- arch/arm64/include/asm/kvm_rme.h | 19 +++++ arch/arm64/kvm/mmu.c | 7 +- arch/arm64/kvm/rme.c | 139 +++++++++++++++++++++++++++++++ 3 files changed, 162 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/kvm_rme.h b/arch/arm64/include/asm/kvm_rme.h index a6318af3ed11..eea5118dfa8a 100644 --- a/arch/arm64/include/asm/kvm_rme.h +++ b/arch/arm64/include/asm/kvm_rme.h @@ -35,5 +35,24 @@ u32 kvm_realm_ipa_limit(void); int kvm_realm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap); int kvm_init_realm_vm(struct kvm *kvm); void kvm_destroy_realm(struct kvm *kvm); +void kvm_realm_destroy_rtts(struct realm *realm, u32 ia_bits, u32 start_level); + +#define RME_RTT_BLOCK_LEVEL 2 +#define RME_RTT_MAX_LEVEL 3 + +#define RME_PAGE_SHIFT 12 +#define RME_PAGE_SIZE BIT(RME_PAGE_SHIFT)
Can we use PAGE_SIZE and PAGE_SHIFT instead of redefining? May be we can use them to define RME_PAGE_SIZE and RME_PAGE_SHIFT.
+/* See ARM64_HW_PGTABLE_LEVEL_SHIFT() */ +#define RME_RTT_LEVEL_SHIFT(l) \ + ((RME_PAGE_SHIFT - 3) * (4 - (l)) + 3)
Instead of defining again, can we define to ARM64_HW_PGTABLE_LEVEL_SHIFT?
+#define RME_L2_BLOCK_SIZE BIT(RME_RTT_LEVEL_SHIFT(2)) + +static inline unsigned long rme_rtt_level_mapsize(int level) +{ + if (WARN_ON(level > RME_RTT_MAX_LEVEL)) + return RME_PAGE_SIZE; + + return (1UL << RME_RTT_LEVEL_SHIFT(level)); +}#endifdiff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 22c00274884a..f29558c5dcbc 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -834,16 +834,17 @@ void stage2_unmap_vm(struct kvm *kvm) void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu) { struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu); - struct kvm_pgtable *pgt = NULL; + struct kvm_pgtable *pgt;write_lock(&kvm->mmu_lock);+ pgt = mmu->pgt; if (kvm_is_realm(kvm) && kvm_realm_state(kvm) != REALM_STATE_DYING) { - /* TODO: teardown rtts */ write_unlock(&kvm->mmu_lock); + kvm_realm_destroy_rtts(&kvm->arch.realm, pgt->ia_bits, + pgt->start_level); return; } - pgt = mmu->pgt; if (pgt) { mmu->pgd_phys = 0; mmu->pgt = NULL; diff --git a/arch/arm64/kvm/rme.c b/arch/arm64/kvm/rme.c index 0c9d70e4d9e6..f7b0e5a779f8 100644 --- a/arch/arm64/kvm/rme.c +++ b/arch/arm64/kvm/rme.c @@ -73,6 +73,28 @@ static int rmi_check_version(void) return 0; }+static void realm_destroy_undelegate_range(struct realm *realm,+ unsigned long ipa, + unsigned long addr, + ssize_t size) +{ + unsigned long rd = virt_to_phys(realm->rd); + int ret; + + while (size > 0) { + ret = rmi_data_destroy(rd, ipa); + WARN_ON(ret); + ret = rmi_granule_undelegate(addr); + + if (ret) + get_page(phys_to_page(addr)); + + addr += PAGE_SIZE; + ipa += PAGE_SIZE; + size -= PAGE_SIZE; + } +} + static unsigned long create_realm_feat_reg0(struct kvm *kvm) { unsigned long ia_bits = VTCR_EL2_IPA(kvm->arch.vtcr); @@ -170,6 +192,123 @@ static int realm_create_rd(struct kvm *kvm) return r; }+static int realm_rtt_destroy(struct realm *realm, unsigned long addr,+ int level, phys_addr_t rtt_granule) +{ + addr = ALIGN_DOWN(addr, rme_rtt_level_mapsize(level - 1)); + return rmi_rtt_destroy(rtt_granule, virt_to_phys(realm->rd), addr, + level); +} + +static int realm_destroy_free_rtt(struct realm *realm, unsigned long addr, + int level, phys_addr_t rtt_granule) +{ + if (realm_rtt_destroy(realm, addr, level, rtt_granule)) + return -ENXIO; + if (!WARN_ON(rmi_granule_undelegate(rtt_granule))) + put_page(phys_to_page(rtt_granule)); + + return 0; +} + +static int realm_rtt_create(struct realm *realm, + unsigned long addr, + int level, + phys_addr_t phys) +{ + addr = ALIGN_DOWN(addr, rme_rtt_level_mapsize(level - 1)); + return rmi_rtt_create(phys, virt_to_phys(realm->rd), addr, level); +} + +static int realm_tear_down_rtt_range(struct realm *realm, int level, + unsigned long start, unsigned long end) +{ + phys_addr_t rd = virt_to_phys(realm->rd); + ssize_t map_size = rme_rtt_level_mapsize(level); + unsigned long addr, next_addr; + bool failed = false; + + for (addr = start; addr < end; addr = next_addr) { + phys_addr_t rtt_addr, tmp_rtt; + struct rtt_entry rtt; + unsigned long end_addr; + + next_addr = ALIGN(addr + 1, map_size); + + end_addr = min(next_addr, end); + + if (rmi_rtt_read_entry(rd, ALIGN_DOWN(addr, map_size), + level, &rtt)) { + failed = true; + continue; + } + + rtt_addr = rmi_rtt_get_phys(&rtt); + WARN_ON(level != rtt.walk_level); + + switch (rtt.state) { + case RMI_UNASSIGNED: + case RMI_DESTROYED: + break; + case RMI_TABLE: + if (realm_tear_down_rtt_range(realm, level + 1, + addr, end_addr)) { + failed = true; + break; + } + if (IS_ALIGNED(addr, map_size) && + next_addr <= end && + realm_destroy_free_rtt(realm, addr, level + 1, + rtt_addr)) + failed = true; + break; + case RMI_ASSIGNED: + WARN_ON(!rtt_addr); + /* + * If there is a block mapping, break it now, using the + * spare_page. We are sure to have a valid delegated + * page at spare_page before we enter here, otherwise + * WARN once, which will be followed by further + * warnings. + */ + tmp_rtt = realm->spare_page; + if (level == 2 && + !WARN_ON_ONCE(tmp_rtt == PHYS_ADDR_MAX) && + realm_rtt_create(realm, addr, + RME_RTT_MAX_LEVEL, tmp_rtt)) { + WARN_ON(1); + failed = true; + break; + } + realm_destroy_undelegate_range(realm, addr, + rtt_addr, map_size); + /* + * Collapse the last level table and make the spare page + * reusable again. + */ + if (level == 2 && + realm_rtt_destroy(realm, addr, RME_RTT_MAX_LEVEL, + tmp_rtt)) + failed = true; + break; + case RMI_VALID_NS: + WARN_ON(rmi_rtt_unmap_unprotected(rd, addr, level)); + break; + default: + WARN_ON(1); + failed = true; + break; + } + } + + return failed ? -EINVAL : 0; +} + +void kvm_realm_destroy_rtts(struct realm *realm, u32 ia_bits, u32 start_level) +{ + realm_tear_down_rtt_range(realm, start_level, 0, (1UL << ia_bits)); +} + /* Protects access to rme_vmid_bitmap */ static DEFINE_SPINLOCK(rme_vmid_lock); static unsigned long *rme_vmid_bitmap;
Thanks, Ganapat
