* [PATCH v4 0/3] hvf: map granule abstraction, configurable IPA, and MAP_FIXED alignment fix
@ 2026-03-17 17:48 Lucas Amaral
2026-03-17 17:48 ` [PATCH v4 1/3] virtio-gpu: validate host page alignment for MAP_FIXED blobs Lucas Amaral
` (3 more replies)
0 siblings, 4 replies; 8+ messages in thread
From: Lucas Amaral @ 2026-03-17 17:48 UTC (permalink / raw)
To: qemu-devel; +Cc: qemu-arm, agraf, peter.maydell, mohamed, Lucas Amaral
Fix a bug in the MAP_FIXED blob mapping path (introduced by 4eb0aace)
where non-host-page-aligned offsets cause mmap(MAP_FIXED) to fail with
EINVAL. This affects any host where the page size exceeds the guest's
(ARM64 with 16KB/64KB pages, macOS ARM64).
This series introduces:
1. MAP_FIXED alignment validation in virtio-gpu: check that both
offset and blob size are aligned to the host page size before
calling virgl_renderer_resource_map_fixed(). When not aligned,
fall through to the subregion method (which works at any
alignment).
2. A map granule abstraction (hvf_set/get_map_granule) replacing
hardcoded qemu_real_host_page_size() calls in HVF memory mapping.
Non-aligned regions return early instead of proceeding with
add=false (which attempted an unnecessary unmap).
An 'ipa-granule' property (auto, 4k, 16k) on the HVF accelerator
object allows opt-in configuration:
-accel hvf,ipa-granule=4k
The property follows the kvm_arch_accel_class_init() pattern:
ARM registers the property in hvf_arch_accel_class_init(), x86
provides an empty stub.
3. macOS 26 IPA granule support via hv_vm_config_set_ipa_granule(),
reading the ipa-granule property to select HV_IPA_GRANULE_4KB or
HV_IPA_GRANULE_16KB. Falls back with a warning on macOS < 26.
Dependencies: none.
Changes v3 -> v4:
- Rebased onto current master (no code changes)
- Resent as new top-level thread per Alex Bennée's feedback
Changes v2 -> v3:
- Rebased on current master
- Add MAP_FIXED alignment validation (new patch 1)
- Move #ifdef __aarch64__ property code into hvf_arch_accel_class_init
following kvm_arch_accel_class_init() pattern (x86 empty stub)
- Use MAC_OS_VERSION_26_0 named constant
- Remove Venus blob mapping warning
Changes v1 -> v2 (Mohamed Mosaad review):
- Replace hardcoded 4KB with configurable ipa-granule property
(auto, 4k, 16k) on the HVF accelerator object.
- 'auto' defaults to host page size; explicit values opt in.
- Add fallback warning when macOS < 26 can't honor the request.
- Add Venus blob mapping safety warning.
- Use KiB constants instead of magic numbers.
Lucas Amaral (3):
virtio-gpu: validate host page alignment for MAP_FIXED blobs
accel/hvf: introduce map granule abstraction and IPA property
target/arm/hvf: configure IPA granule on macOS 26
accel/hvf/hvf-all.c | 30 +++++++++++++--
hw/display/virtio-gpu-virgl.c | 45 +++++++++++++---------
include/system/hvf.h | 15 ++++++++
include/system/hvf_int.h | 2 +
target/arm/hvf/hvf.c | 72 +++++++++++++++++++++++++++++++++++
target/i386/hvf/hvf.c | 4 ++
6 files changed, 147 insertions(+), 21 deletions(-)
--
2.52.0
^ permalink raw reply [flat|nested] 8+ messages in thread* [PATCH v4 1/3] virtio-gpu: validate host page alignment for MAP_FIXED blobs 2026-03-17 17:48 [PATCH v4 0/3] hvf: map granule abstraction, configurable IPA, and MAP_FIXED alignment fix Lucas Amaral @ 2026-03-17 17:48 ` Lucas Amaral 2026-03-17 17:48 ` [PATCH v4 2/3] accel/hvf: introduce map granule abstraction and IPA property Lucas Amaral ` (2 subsequent siblings) 3 siblings, 0 replies; 8+ messages in thread From: Lucas Amaral @ 2026-03-17 17:48 UTC (permalink / raw) To: qemu-devel; +Cc: qemu-arm, agraf, peter.maydell, mohamed, Lucas Amaral Commit 4eb0aace ("virtio-gpu: Support mapping hostmem blobs with map_fixed") uses mmap(MAP_FIXED) to map blob resources into a pre-allocated hostmem region. Both the offset and size passed to mmap must be aligned to the host page size, but the code does not validate this. On hosts where qemu_real_host_page_size() exceeds the guest's page size (e.g. ARM64 with 16KB or 64KB pages, macOS ARM64), the guest may provide blob offsets aligned to its own page size (4KB) but not to the host's. This causes mmap(MAP_FIXED) to fail with EINVAL, and the subsequent unmap (which also uses mmap MAP_FIXED) fails the same way, producing: virtio_gpu_virgl_unmap_resource_blob: failed to unmap(fixed) virgl resource: Invalid argument Add an alignment check before attempting MAP_FIXED. When the offset or blob size is not host-page-aligned, skip the MAP_FIXED path and fall through to the existing subregion method, which handles any alignment. Fixes: 4eb0aace ("virtio-gpu: Support mapping hostmem blobs with map_fixed") Signed-off-by: Lucas Amaral <lucaaamaral@gmail.com> --- hw/display/virtio-gpu-virgl.c | 45 +++++++++++++++++++++-------------- 1 file changed, 27 insertions(+), 18 deletions(-) diff --git a/hw/display/virtio-gpu-virgl.c b/hw/display/virtio-gpu-virgl.c index b7a2d160..f6583b48 100644 --- a/hw/display/virtio-gpu-virgl.c +++ b/hw/display/virtio-gpu-virgl.c @@ -185,25 +185,34 @@ virtio_gpu_virgl_map_resource_blob(VirtIOGPU *g, return -EBUSY; } - ret = virgl_renderer_resource_map_fixed(res->base.resource_id, - gl->hostmem_mmap + offset); - switch (ret) { - case 0: - res->map_fixed = gl->hostmem_mmap + offset; - return 0; - - case -EOPNOTSUPP: - /* - * MAP_FIXED is unsupported by this resource. - * Mapping falls back to a blob subregion method in that case. - */ - break; + /* + * MAP_FIXED requires host-page-aligned offset and size. Hosts with + * page sizes larger than the guest's (e.g. 16KB on ARM64) may receive + * non-aligned blob offsets. Fall through to the subregion method when + * alignment requirements are not met. + */ + if (QEMU_IS_ALIGNED(offset, qemu_real_host_page_size()) && + QEMU_IS_ALIGNED(res->base.blob_size, qemu_real_host_page_size())) { + ret = virgl_renderer_resource_map_fixed(res->base.resource_id, + gl->hostmem_mmap + offset); + switch (ret) { + case 0: + res->map_fixed = gl->hostmem_mmap + offset; + return 0; + + case -EOPNOTSUPP: + /* + * MAP_FIXED is unsupported by this resource. + * Mapping falls back to a blob subregion method in that case. + */ + break; - default: - qemu_log_mask(LOG_GUEST_ERROR, - "%s: failed to map(fixed) virgl resource: %s\n", - __func__, strerror(-ret)); - return ret; + default: + qemu_log_mask(LOG_GUEST_ERROR, + "%s: failed to map(fixed) virgl resource: %s\n", + __func__, strerror(-ret)); + return ret; + } } #endif -- 2.52.0 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v4 2/3] accel/hvf: introduce map granule abstraction and IPA property 2026-03-17 17:48 [PATCH v4 0/3] hvf: map granule abstraction, configurable IPA, and MAP_FIXED alignment fix Lucas Amaral 2026-03-17 17:48 ` [PATCH v4 1/3] virtio-gpu: validate host page alignment for MAP_FIXED blobs Lucas Amaral @ 2026-03-17 17:48 ` Lucas Amaral 2026-03-17 17:48 ` [PATCH v4 3/3] target/arm/hvf: configure IPA granule on macOS 26 Lucas Amaral 2026-04-24 7:38 ` [PATCH v4 0/3] hvf: map granule abstraction, configurable IPA, and MAP_FIXED alignment fix Manos Pitsidianakis 3 siblings, 0 replies; 8+ messages in thread From: Lucas Amaral @ 2026-03-17 17:48 UTC (permalink / raw) To: qemu-devel Cc: qemu-arm, agraf, peter.maydell, mohamed, Lucas Amaral, Lucas Amaral Add a map granule abstraction that decouples HVF memory mapping alignment from the host page size. On ARM64, Apple Silicon supports stage-2 translation with 4KB page granules regardless of the host OS page size (16KB on macOS). This allows running guests with 4KB pages without interior mapping failures. Introduce hvf_set_map_granule()/hvf_get_map_granule() in hvf-all.c to replace hard-coded qemu_real_host_page_size() references in do_hv_vm_protect() and hvf_set_phys_mem(). When the granule is not explicitly configured, fall back to host page size to preserve the previous behaviour. Add an "ipa-granule" accelerator property (auto, 4k, 16k) following the established kvm_arch_accel_class_init() pattern: ARM registers the property in hvf_arch_accel_class_init(), x86 provides an empty stub. This avoids #ifdef __aarch64__ in common code while keeping a single hvf-all.c shared by both targets. Fix hvf_set_phys_mem() to return early for non-aligned regions instead of clearing the add flag, which previously fell through to an incorrect unmap of a region that was never mapped. Signed-off-by: Lucas Amaral <lucas@lucasamaral.com> --- accel/hvf/hvf-all.c | 30 +++++++++++++++++++++++++++--- include/system/hvf.h | 15 +++++++++++++++ include/system/hvf_int.h | 2 ++ target/arm/hvf/hvf.c | 40 ++++++++++++++++++++++++++++++++++++++++ target/i386/hvf/hvf.c | 4 ++++ 5 files changed, 88 insertions(+), 3 deletions(-) diff --git a/accel/hvf/hvf-all.c b/accel/hvf/hvf-all.c index 5f357c6d..d745fefd 100644 --- a/accel/hvf/hvf-all.c +++ b/accel/hvf/hvf-all.c @@ -10,6 +10,8 @@ #include "qemu/osdep.h" #include "qemu/error-report.h" +#include "qemu/units.h" +#include "qapi/error.h" #include "accel/accel-ops.h" #include "exec/cpu-common.h" #include "system/address-spaces.h" @@ -22,6 +24,21 @@ bool hvf_allowed; +static uint64_t hvf_map_granule; + +void hvf_set_map_granule(uint64_t size) +{ + hvf_map_granule = size; +} + +uint64_t hvf_get_map_granule(void) +{ + if (!hvf_map_granule) { + return qemu_real_host_page_size(); + } + return hvf_map_granule; +} + const char *hvf_return_string(hv_return_t ret) { switch (ret) { @@ -53,7 +70,7 @@ void assert_hvf_ok_impl(hv_return_t ret, const char *file, unsigned int line, static void do_hv_vm_protect(hwaddr start, size_t size, hv_memory_flags_t flags) { - intptr_t page_mask = qemu_real_host_page_mask(); + intptr_t page_mask = -(intptr_t)hvf_get_map_granule(); hv_return_t ret; trace_hvf_vm_protect(start, size, flags, @@ -83,7 +100,7 @@ static void hvf_set_phys_mem(MemoryRegionSection *section, bool add) MemoryRegion *area = section->mr; bool writable = !area->readonly && !area->rom_device; hv_memory_flags_t flags; - uint64_t page_size = qemu_real_host_page_size(); + uint64_t page_size = hvf_get_map_granule(); uint64_t gpa = section->offset_within_address_space; uint64_t size = int128_get64(section->size); hv_return_t ret; @@ -104,7 +121,7 @@ static void hvf_set_phys_mem(MemoryRegionSection *section, bool add) if (!QEMU_IS_ALIGNED(size, page_size) || !QEMU_IS_ALIGNED(gpa, page_size)) { /* Not page aligned, so we can not map as RAM */ - add = false; + return; } if (!add) { @@ -186,6 +203,11 @@ static int hvf_accel_init(AccelState *as, MachineState *ms) int pa_range = 36; MachineClass *mc = MACHINE_GET_CLASS(ms); + /* Resolve ipa-granule=auto → host page size */ + if (!s->ipa_granule) { + s->ipa_granule = qemu_real_host_page_size(); + } + hvf_set_map_granule(s->ipa_granule); if (mc->get_physical_address_range) { pa_range = mc->get_physical_address_range(ms, @@ -223,6 +245,8 @@ static void hvf_accel_class_init(ObjectClass *oc, const void *data) ac->init_machine = hvf_accel_init; ac->allowed = &hvf_allowed; ac->gdbstub_supported_sstep_flags = hvf_gdbstub_sstep_flags; + + hvf_arch_accel_class_init(oc); } static const TypeInfo hvf_accel_type = { diff --git a/include/system/hvf.h b/include/system/hvf.h index d3dcf088..3c4c3b89 100644 --- a/include/system/hvf.h +++ b/include/system/hvf.h @@ -36,4 +36,19 @@ typedef struct HVFState HVFState; DECLARE_INSTANCE_CHECKER(HVFState, HVF_STATE, TYPE_HVF_ACCEL) +#ifdef CONFIG_HVF_IS_POSSIBLE +/* + * Minimum alignment for hv_vm_map(). Returns the configured IPA granule + * or host page size if not set. + */ +void hvf_set_map_granule(uint64_t size); +uint64_t hvf_get_map_granule(void); +#else +static inline void hvf_set_map_granule(uint64_t size) {} +static inline uint64_t hvf_get_map_granule(void) +{ + return qemu_real_host_page_size(); +} +#endif + #endif diff --git a/include/system/hvf_int.h b/include/system/hvf_int.h index 2621164c..9589b022 100644 --- a/include/system/hvf_int.h +++ b/include/system/hvf_int.h @@ -38,6 +38,7 @@ struct HVFState { hvf_vcpu_caps *hvf_caps; uint64_t vtimer_offset; + uint32_t ipa_granule; QTAILQ_HEAD(, hvf_sw_breakpoint) hvf_sw_breakpoints; }; extern HVFState *hvf_state; @@ -57,6 +58,7 @@ void assert_hvf_ok_impl(hv_return_t ret, const char *file, unsigned int line, const char *hvf_return_string(hv_return_t ret); int hvf_arch_init(void); hv_return_t hvf_arch_vm_create(MachineState *ms, uint32_t pa_range); +void hvf_arch_accel_class_init(ObjectClass *oc); uint32_t hvf_arch_get_default_ipa_bit_size(void); uint32_t hvf_arch_get_max_ipa_bit_size(void); void hvf_kick_vcpu_thread(CPUState *cpu); diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c index 5fc8f6bb..1ba5bbf3 100644 --- a/target/arm/hvf/hvf.c +++ b/target/arm/hvf/hvf.c @@ -12,6 +12,8 @@ #include "qemu/osdep.h" #include "qemu/error-report.h" #include "qemu/log.h" +#include "qemu/units.h" +#include "qapi/error.h" #include "system/runstate.h" #include "system/hvf.h" @@ -1218,6 +1220,44 @@ void hvf_arch_vcpu_destroy(CPUState *cpu) assert_hvf_ok(ret); } +static char *hvf_get_ipa_granule(Object *obj, Error **errp) +{ + HVFState *s = HVF_STATE(obj); + + if (s->ipa_granule == 4 * KiB) { + return g_strdup("4k"); + } + if (s->ipa_granule == 16 * KiB) { + return g_strdup("16k"); + } + return g_strdup("auto"); +} + +static void hvf_set_ipa_granule(Object *obj, const char *value, Error **errp) +{ + HVFState *s = HVF_STATE(obj); + + if (!strcmp(value, "auto")) { + s->ipa_granule = 0; + } else if (!strcmp(value, "4k")) { + s->ipa_granule = 4 * KiB; + } else if (!strcmp(value, "16k")) { + s->ipa_granule = 16 * KiB; + } else { + error_setg(errp, "invalid ipa-granule: '%s' (use auto, 4k, 16k)", + value); + } +} + +void hvf_arch_accel_class_init(ObjectClass *oc) +{ + object_class_property_add_str(oc, "ipa-granule", + hvf_get_ipa_granule, + hvf_set_ipa_granule); + object_class_property_set_description(oc, "ipa-granule", + "IPA granule for HVF stage-2 translation (auto, 4k, 16k)"); +} + hv_return_t hvf_arch_vm_create(MachineState *ms, uint32_t pa_range) { hv_return_t ret; diff --git a/target/i386/hvf/hvf.c b/target/i386/hvf/hvf.c index c0d028b1..565c79b3 100644 --- a/target/i386/hvf/hvf.c +++ b/target/i386/hvf/hvf.c @@ -228,6 +228,10 @@ int hvf_arch_init(void) return 0; } +void hvf_arch_accel_class_init(ObjectClass *oc) +{ +} + /* 48-bit on all Intel Macs. Function currently unused. */ uint32_t hvf_arch_get_default_ipa_bit_size(void) { -- 2.52.0 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v4 3/3] target/arm/hvf: configure IPA granule on macOS 26 2026-03-17 17:48 [PATCH v4 0/3] hvf: map granule abstraction, configurable IPA, and MAP_FIXED alignment fix Lucas Amaral 2026-03-17 17:48 ` [PATCH v4 1/3] virtio-gpu: validate host page alignment for MAP_FIXED blobs Lucas Amaral 2026-03-17 17:48 ` [PATCH v4 2/3] accel/hvf: introduce map granule abstraction and IPA property Lucas Amaral @ 2026-03-17 17:48 ` Lucas Amaral 2026-04-24 7:38 ` [PATCH v4 0/3] hvf: map granule abstraction, configurable IPA, and MAP_FIXED alignment fix Manos Pitsidianakis 3 siblings, 0 replies; 8+ messages in thread From: Lucas Amaral @ 2026-03-17 17:48 UTC (permalink / raw) To: qemu-devel Cc: qemu-arm, agraf, peter.maydell, mohamed, Lucas Amaral, Lucas Amaral Read the ipa-granule property (set by hvf_accel_init) and configure the HVF stage-2 translation granule via hv_vm_config_set_ipa_granule() on macOS 26+. When ipa-granule=4k, use HV_IPA_GRANULE_4KB to allow HVF to map memory at 4KB granularity, matching 4KB-page guests on hosts with larger page sizes. If macOS < 26 and a sub-host-page granule was requested, warn and fall back to the host page size. Signed-off-by: Lucas Amaral <lucas@lucasamaral.com> --- target/arm/hvf/hvf.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c index 1ba5bbf3..e3b1e3e1 100644 --- a/target/arm/hvf/hvf.c +++ b/target/arm/hvf/hvf.c @@ -1269,6 +1269,38 @@ hv_return_t hvf_arch_vm_create(MachineState *ms, uint32_t pa_range) } chosen_ipa_bit_size = pa_range; + /* + * Configure IPA granule from the ipa-granule property. + * hvf_get_map_granule() was set by hvf_accel_init() before this call. + */ + { + uint64_t granule = hvf_get_map_granule(); + bool granule_set = false; + +#if defined(__MAC_OS_X_VERSION_MAX_ALLOWED) && \ + (__MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_VERSION_26_0) + if (__builtin_available(macOS 26, *)) { + hv_ipa_granule_t hv_gran = (granule <= 4 * KiB) + ? HV_IPA_GRANULE_4KB : HV_IPA_GRANULE_16KB; + ret = hv_vm_config_set_ipa_granule(config, hv_gran); + if (ret != HV_SUCCESS) { + error_report("HVF: failed to set IPA granule: %s", + hvf_return_string(ret)); + goto cleanup; + } + granule_set = true; + } +#endif + + if (!granule_set && granule < qemu_real_host_page_size()) { + warn_report("HVF: ipa-granule=%zuKB requested but macOS < 26; " + "falling back to host page size (%zuKB)", + (size_t)(granule / KiB), + (size_t)(qemu_real_host_page_size() / KiB)); + hvf_set_map_granule(qemu_real_host_page_size()); + } + } + ret = hv_vm_create(config); cleanup: -- 2.52.0 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v4 0/3] hvf: map granule abstraction, configurable IPA, and MAP_FIXED alignment fix 2026-03-17 17:48 [PATCH v4 0/3] hvf: map granule abstraction, configurable IPA, and MAP_FIXED alignment fix Lucas Amaral ` (2 preceding siblings ...) 2026-03-17 17:48 ` [PATCH v4 3/3] target/arm/hvf: configure IPA granule on macOS 26 Lucas Amaral @ 2026-04-24 7:38 ` Manos Pitsidianakis 3 siblings, 0 replies; 8+ messages in thread From: Manos Pitsidianakis @ 2026-04-24 7:38 UTC (permalink / raw) To: Lucas Amaral; +Cc: qemu-devel, qemu-arm, agraf, peter.maydell, mohamed On Tue, Mar 17, 2026 at 7:50 PM Lucas Amaral <lucaaamaral@gmail.com> wrote: > > Fix a bug in the MAP_FIXED blob mapping path (introduced by 4eb0aace) > where non-host-page-aligned offsets cause mmap(MAP_FIXED) to fail with > EINVAL. This affects any host where the page size exceeds the guest's > (ARM64 with 16KB/64KB pages, macOS ARM64). FYI VIRTIO 1.4 has a VIRTIO_GPU_F_BLOB_ALIGNMENT feature that allows the device to expose the necessary host alignment in a configuration space. > > This series introduces: > > 1. MAP_FIXED alignment validation in virtio-gpu: check that both > offset and blob size are aligned to the host page size before > calling virgl_renderer_resource_map_fixed(). When not aligned, > fall through to the subregion method (which works at any > alignment). > > 2. A map granule abstraction (hvf_set/get_map_granule) replacing > hardcoded qemu_real_host_page_size() calls in HVF memory mapping. > Non-aligned regions return early instead of proceeding with > add=false (which attempted an unnecessary unmap). > An 'ipa-granule' property (auto, 4k, 16k) on the HVF accelerator > object allows opt-in configuration: > > -accel hvf,ipa-granule=4k > > The property follows the kvm_arch_accel_class_init() pattern: > ARM registers the property in hvf_arch_accel_class_init(), x86 > provides an empty stub. > > 3. macOS 26 IPA granule support via hv_vm_config_set_ipa_granule(), > reading the ipa-granule property to select HV_IPA_GRANULE_4KB or > HV_IPA_GRANULE_16KB. Falls back with a warning on macOS < 26. > > Dependencies: none. > > Changes v3 -> v4: > - Rebased onto current master (no code changes) > - Resent as new top-level thread per Alex Bennée's feedback > > Changes v2 -> v3: > - Rebased on current master > - Add MAP_FIXED alignment validation (new patch 1) > - Move #ifdef __aarch64__ property code into hvf_arch_accel_class_init > following kvm_arch_accel_class_init() pattern (x86 empty stub) > - Use MAC_OS_VERSION_26_0 named constant > - Remove Venus blob mapping warning > > Changes v1 -> v2 (Mohamed Mosaad review): > - Replace hardcoded 4KB with configurable ipa-granule property > (auto, 4k, 16k) on the HVF accelerator object. > - 'auto' defaults to host page size; explicit values opt in. > - Add fallback warning when macOS < 26 can't honor the request. > - Add Venus blob mapping safety warning. > - Use KiB constants instead of magic numbers. > > Lucas Amaral (3): > virtio-gpu: validate host page alignment for MAP_FIXED blobs > accel/hvf: introduce map granule abstraction and IPA property > target/arm/hvf: configure IPA granule on macOS 26 > > accel/hvf/hvf-all.c | 30 +++++++++++++-- > hw/display/virtio-gpu-virgl.c | 45 +++++++++++++--------- > include/system/hvf.h | 15 ++++++++ > include/system/hvf_int.h | 2 + > target/arm/hvf/hvf.c | 72 +++++++++++++++++++++++++++++++++++ > target/i386/hvf/hvf.c | 4 ++ > 6 files changed, 147 insertions(+), 21 deletions(-) > > -- > 2.52.0 > > -- Manos Pitsidianakis Emulation and Virtualization Engineer at Linaro Ltd ^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v4 0/3] hvf: map granule abstraction, configurable IPA, and MAP_FIXED alignment fix
@ 2026-03-17 17:57 Lucas Amaral
2026-03-17 17:57 ` [PATCH v4 2/3] accel/hvf: introduce map granule abstraction and IPA property Lucas Amaral
0 siblings, 1 reply; 8+ messages in thread
From: Lucas Amaral @ 2026-03-17 17:57 UTC (permalink / raw)
To: qemu-devel; +Cc: qemu-arm, agraf, peter.maydell, mohamed, Lucas Amaral
Fix a bug in the MAP_FIXED blob mapping path (introduced by 4eb0aace)
where non-host-page-aligned offsets cause mmap(MAP_FIXED) to fail with
EINVAL. This affects any host where the page size exceeds the guest's
(ARM64 with 16KB/64KB pages, macOS ARM64).
This series introduces:
1. MAP_FIXED alignment validation in virtio-gpu: check that both
offset and blob size are aligned to the host page size before
calling virgl_renderer_resource_map_fixed(). When not aligned,
fall through to the subregion method (which works at any
alignment).
2. A map granule abstraction (hvf_set/get_map_granule) replacing
hardcoded qemu_real_host_page_size() calls in HVF memory mapping.
Non-aligned regions return early instead of proceeding with
add=false (which attempted an unnecessary unmap).
An 'ipa-granule' property (auto, 4k, 16k) on the HVF accelerator
object allows opt-in configuration:
-accel hvf,ipa-granule=4k
The property follows the kvm_arch_accel_class_init() pattern:
ARM registers the property in hvf_arch_accel_class_init(), x86
provides an empty stub.
3. macOS 26 IPA granule support via hv_vm_config_set_ipa_granule(),
reading the ipa-granule property to select HV_IPA_GRANULE_4KB or
HV_IPA_GRANULE_16KB. Falls back with a warning on macOS < 26.
Dependencies: none.
Changes v3 -> v4:
- Rebased onto current master (no code changes)
- Fix Signed-off-by email in patches 2/3 and 3/3
- Resent as new top-level thread per Alex Bennée's feedback
Changes v2 -> v3:
- Rebased on current master
- Add MAP_FIXED alignment validation (new patch 1)
- Move #ifdef __aarch64__ property code into hvf_arch_accel_class_init
following kvm_arch_accel_class_init() pattern (x86 empty stub)
- Use MAC_OS_VERSION_26_0 named constant
- Remove Venus blob mapping warning
Changes v1 -> v2 (Mohamed Mosaad review):
- Replace hardcoded 4KB with configurable ipa-granule property
(auto, 4k, 16k) on the HVF accelerator object.
- 'auto' defaults to host page size; explicit values opt in.
- Add fallback warning when macOS < 26 can't honor the request.
- Add Venus blob mapping safety warning.
- Use KiB constants instead of magic numbers.
Lucas Amaral (3):
virtio-gpu: validate host page alignment for MAP_FIXED blobs
accel/hvf: introduce map granule abstraction and IPA property
target/arm/hvf: configure IPA granule on macOS 26
accel/hvf/hvf-all.c | 30 +++++++++++++--
hw/display/virtio-gpu-virgl.c | 45 +++++++++++++---------
include/system/hvf.h | 15 ++++++++
include/system/hvf_int.h | 2 +
target/arm/hvf/hvf.c | 72 +++++++++++++++++++++++++++++++++++
target/i386/hvf/hvf.c | 4 ++
6 files changed, 147 insertions(+), 21 deletions(-)
--
2.52.0
^ permalink raw reply [flat|nested] 8+ messages in thread* [PATCH v4 2/3] accel/hvf: introduce map granule abstraction and IPA property 2026-03-17 17:57 Lucas Amaral @ 2026-03-17 17:57 ` Lucas Amaral 2026-04-23 18:05 ` Alex Bennée 0 siblings, 1 reply; 8+ messages in thread From: Lucas Amaral @ 2026-03-17 17:57 UTC (permalink / raw) To: qemu-devel; +Cc: qemu-arm, agraf, peter.maydell, mohamed, Lucas Amaral Add a map granule abstraction that decouples HVF memory mapping alignment from the host page size. On ARM64, Apple Silicon supports stage-2 translation with 4KB page granules regardless of the host OS page size (16KB on macOS). This allows running guests with 4KB pages without interior mapping failures. Introduce hvf_set_map_granule()/hvf_get_map_granule() in hvf-all.c to replace hard-coded qemu_real_host_page_size() references in do_hv_vm_protect() and hvf_set_phys_mem(). When the granule is not explicitly configured, fall back to host page size to preserve the previous behaviour. Add an "ipa-granule" accelerator property (auto, 4k, 16k) following the established kvm_arch_accel_class_init() pattern: ARM registers the property in hvf_arch_accel_class_init(), x86 provides an empty stub. This avoids #ifdef __aarch64__ in common code while keeping a single hvf-all.c shared by both targets. Fix hvf_set_phys_mem() to return early for non-aligned regions instead of clearing the add flag, which previously fell through to an incorrect unmap of a region that was never mapped. Signed-off-by: Lucas Amaral <lucaaamaral@gmail.com> --- accel/hvf/hvf-all.c | 30 +++++++++++++++++++++++++++--- include/system/hvf.h | 15 +++++++++++++++ include/system/hvf_int.h | 2 ++ target/arm/hvf/hvf.c | 40 ++++++++++++++++++++++++++++++++++++++++ target/i386/hvf/hvf.c | 4 ++++ 5 files changed, 88 insertions(+), 3 deletions(-) diff --git a/accel/hvf/hvf-all.c b/accel/hvf/hvf-all.c index 5f357c6d..d745fefd 100644 --- a/accel/hvf/hvf-all.c +++ b/accel/hvf/hvf-all.c @@ -10,6 +10,8 @@ #include "qemu/osdep.h" #include "qemu/error-report.h" +#include "qemu/units.h" +#include "qapi/error.h" #include "accel/accel-ops.h" #include "exec/cpu-common.h" #include "system/address-spaces.h" @@ -22,6 +24,21 @@ bool hvf_allowed; +static uint64_t hvf_map_granule; + +void hvf_set_map_granule(uint64_t size) +{ + hvf_map_granule = size; +} + +uint64_t hvf_get_map_granule(void) +{ + if (!hvf_map_granule) { + return qemu_real_host_page_size(); + } + return hvf_map_granule; +} + const char *hvf_return_string(hv_return_t ret) { switch (ret) { @@ -53,7 +70,7 @@ void assert_hvf_ok_impl(hv_return_t ret, const char *file, unsigned int line, static void do_hv_vm_protect(hwaddr start, size_t size, hv_memory_flags_t flags) { - intptr_t page_mask = qemu_real_host_page_mask(); + intptr_t page_mask = -(intptr_t)hvf_get_map_granule(); hv_return_t ret; trace_hvf_vm_protect(start, size, flags, @@ -83,7 +100,7 @@ static void hvf_set_phys_mem(MemoryRegionSection *section, bool add) MemoryRegion *area = section->mr; bool writable = !area->readonly && !area->rom_device; hv_memory_flags_t flags; - uint64_t page_size = qemu_real_host_page_size(); + uint64_t page_size = hvf_get_map_granule(); uint64_t gpa = section->offset_within_address_space; uint64_t size = int128_get64(section->size); hv_return_t ret; @@ -104,7 +121,7 @@ static void hvf_set_phys_mem(MemoryRegionSection *section, bool add) if (!QEMU_IS_ALIGNED(size, page_size) || !QEMU_IS_ALIGNED(gpa, page_size)) { /* Not page aligned, so we can not map as RAM */ - add = false; + return; } if (!add) { @@ -186,6 +203,11 @@ static int hvf_accel_init(AccelState *as, MachineState *ms) int pa_range = 36; MachineClass *mc = MACHINE_GET_CLASS(ms); + /* Resolve ipa-granule=auto → host page size */ + if (!s->ipa_granule) { + s->ipa_granule = qemu_real_host_page_size(); + } + hvf_set_map_granule(s->ipa_granule); if (mc->get_physical_address_range) { pa_range = mc->get_physical_address_range(ms, @@ -223,6 +245,8 @@ static void hvf_accel_class_init(ObjectClass *oc, const void *data) ac->init_machine = hvf_accel_init; ac->allowed = &hvf_allowed; ac->gdbstub_supported_sstep_flags = hvf_gdbstub_sstep_flags; + + hvf_arch_accel_class_init(oc); } static const TypeInfo hvf_accel_type = { diff --git a/include/system/hvf.h b/include/system/hvf.h index d3dcf088..3c4c3b89 100644 --- a/include/system/hvf.h +++ b/include/system/hvf.h @@ -36,4 +36,19 @@ typedef struct HVFState HVFState; DECLARE_INSTANCE_CHECKER(HVFState, HVF_STATE, TYPE_HVF_ACCEL) +#ifdef CONFIG_HVF_IS_POSSIBLE +/* + * Minimum alignment for hv_vm_map(). Returns the configured IPA granule + * or host page size if not set. + */ +void hvf_set_map_granule(uint64_t size); +uint64_t hvf_get_map_granule(void); +#else +static inline void hvf_set_map_granule(uint64_t size) {} +static inline uint64_t hvf_get_map_granule(void) +{ + return qemu_real_host_page_size(); +} +#endif + #endif diff --git a/include/system/hvf_int.h b/include/system/hvf_int.h index 2621164c..9589b022 100644 --- a/include/system/hvf_int.h +++ b/include/system/hvf_int.h @@ -38,6 +38,7 @@ struct HVFState { hvf_vcpu_caps *hvf_caps; uint64_t vtimer_offset; + uint32_t ipa_granule; QTAILQ_HEAD(, hvf_sw_breakpoint) hvf_sw_breakpoints; }; extern HVFState *hvf_state; @@ -57,6 +58,7 @@ void assert_hvf_ok_impl(hv_return_t ret, const char *file, unsigned int line, const char *hvf_return_string(hv_return_t ret); int hvf_arch_init(void); hv_return_t hvf_arch_vm_create(MachineState *ms, uint32_t pa_range); +void hvf_arch_accel_class_init(ObjectClass *oc); uint32_t hvf_arch_get_default_ipa_bit_size(void); uint32_t hvf_arch_get_max_ipa_bit_size(void); void hvf_kick_vcpu_thread(CPUState *cpu); diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c index 5fc8f6bb..1ba5bbf3 100644 --- a/target/arm/hvf/hvf.c +++ b/target/arm/hvf/hvf.c @@ -12,6 +12,8 @@ #include "qemu/osdep.h" #include "qemu/error-report.h" #include "qemu/log.h" +#include "qemu/units.h" +#include "qapi/error.h" #include "system/runstate.h" #include "system/hvf.h" @@ -1218,6 +1220,44 @@ void hvf_arch_vcpu_destroy(CPUState *cpu) assert_hvf_ok(ret); } +static char *hvf_get_ipa_granule(Object *obj, Error **errp) +{ + HVFState *s = HVF_STATE(obj); + + if (s->ipa_granule == 4 * KiB) { + return g_strdup("4k"); + } + if (s->ipa_granule == 16 * KiB) { + return g_strdup("16k"); + } + return g_strdup("auto"); +} + +static void hvf_set_ipa_granule(Object *obj, const char *value, Error **errp) +{ + HVFState *s = HVF_STATE(obj); + + if (!strcmp(value, "auto")) { + s->ipa_granule = 0; + } else if (!strcmp(value, "4k")) { + s->ipa_granule = 4 * KiB; + } else if (!strcmp(value, "16k")) { + s->ipa_granule = 16 * KiB; + } else { + error_setg(errp, "invalid ipa-granule: '%s' (use auto, 4k, 16k)", + value); + } +} + +void hvf_arch_accel_class_init(ObjectClass *oc) +{ + object_class_property_add_str(oc, "ipa-granule", + hvf_get_ipa_granule, + hvf_set_ipa_granule); + object_class_property_set_description(oc, "ipa-granule", + "IPA granule for HVF stage-2 translation (auto, 4k, 16k)"); +} + hv_return_t hvf_arch_vm_create(MachineState *ms, uint32_t pa_range) { hv_return_t ret; diff --git a/target/i386/hvf/hvf.c b/target/i386/hvf/hvf.c index c0d028b1..565c79b3 100644 --- a/target/i386/hvf/hvf.c +++ b/target/i386/hvf/hvf.c @@ -228,6 +228,10 @@ int hvf_arch_init(void) return 0; } +void hvf_arch_accel_class_init(ObjectClass *oc) +{ +} + /* 48-bit on all Intel Macs. Function currently unused. */ uint32_t hvf_arch_get_default_ipa_bit_size(void) { -- 2.52.0 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v4 2/3] accel/hvf: introduce map granule abstraction and IPA property 2026-03-17 17:57 ` [PATCH v4 2/3] accel/hvf: introduce map granule abstraction and IPA property Lucas Amaral @ 2026-04-23 18:05 ` Alex Bennée 2026-04-23 23:44 ` Lucas Amaral 0 siblings, 1 reply; 8+ messages in thread From: Alex Bennée @ 2026-04-23 18:05 UTC (permalink / raw) To: Lucas Amaral; +Cc: qemu-devel, qemu-arm, agraf, peter.maydell, mohamed Lucas Amaral <lucaaamaral@gmail.com> writes: > Add a map granule abstraction that decouples HVF memory mapping > alignment from the host page size. On ARM64, Apple Silicon supports > stage-2 translation with 4KB page granules regardless of the host OS > page size (16KB on macOS). This allows running guests with 4KB pages > without interior mapping failures. > > Introduce hvf_set_map_granule()/hvf_get_map_granule() in hvf-all.c > to replace hard-coded qemu_real_host_page_size() references in > do_hv_vm_protect() and hvf_set_phys_mem(). When the granule is not > explicitly configured, fall back to host page size to preserve the > previous behaviour. > > Add an "ipa-granule" accelerator property (auto, 4k, 16k) following > the established kvm_arch_accel_class_init() pattern: ARM registers > the property in hvf_arch_accel_class_init(), x86 provides an empty > stub. This avoids #ifdef __aarch64__ in common code while keeping > a single hvf-all.c shared by both targets. > > Fix hvf_set_phys_mem() to return early for non-aligned regions instead > of clearing the add flag, which previously fell through to an > incorrect unmap of a region that was never mapped. > > Signed-off-by: Lucas Amaral <lucaaamaral@gmail.com> > --- > accel/hvf/hvf-all.c | 30 +++++++++++++++++++++++++++--- > include/system/hvf.h | 15 +++++++++++++++ > include/system/hvf_int.h | 2 ++ > target/arm/hvf/hvf.c | 40 ++++++++++++++++++++++++++++++++++++++++ > target/i386/hvf/hvf.c | 4 ++++ > 5 files changed, 88 insertions(+), 3 deletions(-) > > diff --git a/accel/hvf/hvf-all.c b/accel/hvf/hvf-all.c > index 5f357c6d..d745fefd 100644 > --- a/accel/hvf/hvf-all.c > +++ b/accel/hvf/hvf-all.c > @@ -10,6 +10,8 @@ > > #include "qemu/osdep.h" > #include "qemu/error-report.h" > +#include "qemu/units.h" > +#include "qapi/error.h" > #include "accel/accel-ops.h" > #include "exec/cpu-common.h" > #include "system/address-spaces.h" > @@ -22,6 +24,21 @@ > > bool hvf_allowed; > > +static uint64_t hvf_map_granule; > + > +void hvf_set_map_granule(uint64_t size) > +{ > + hvf_map_granule = size; > +} > + > +uint64_t hvf_get_map_granule(void) > +{ > + if (!hvf_map_granule) { > + return qemu_real_host_page_size(); > + } > + return hvf_map_granule; > +} > + > const char *hvf_return_string(hv_return_t ret) > { > switch (ret) { > @@ -53,7 +70,7 @@ void assert_hvf_ok_impl(hv_return_t ret, const char *file, unsigned int line, > static void do_hv_vm_protect(hwaddr start, size_t size, > hv_memory_flags_t flags) > { > - intptr_t page_mask = qemu_real_host_page_mask(); > + intptr_t page_mask = -(intptr_t)hvf_get_map_granule(); > hv_return_t ret; > > trace_hvf_vm_protect(start, size, flags, > @@ -83,7 +100,7 @@ static void hvf_set_phys_mem(MemoryRegionSection *section, bool add) > MemoryRegion *area = section->mr; > bool writable = !area->readonly && !area->rom_device; > hv_memory_flags_t flags; > - uint64_t page_size = qemu_real_host_page_size(); > + uint64_t page_size = hvf_get_map_granule(); > uint64_t gpa = section->offset_within_address_space; > uint64_t size = int128_get64(section->size); > hv_return_t ret; > @@ -104,7 +121,7 @@ static void hvf_set_phys_mem(MemoryRegionSection *section, bool add) > if (!QEMU_IS_ALIGNED(size, page_size) || > !QEMU_IS_ALIGNED(gpa, page_size)) { > /* Not page aligned, so we can not map as RAM */ > - add = false; > + return; > } > > if (!add) { > @@ -186,6 +203,11 @@ static int hvf_accel_init(AccelState *as, MachineState *ms) > int pa_range = 36; > MachineClass *mc = MACHINE_GET_CLASS(ms); > > + /* Resolve ipa-granule=auto → host page size */ > + if (!s->ipa_granule) { > + s->ipa_granule = qemu_real_host_page_size(); > + } > + hvf_set_map_granule(s->ipa_granule); > > if (mc->get_physical_address_range) { > pa_range = mc->get_physical_address_range(ms, > @@ -223,6 +245,8 @@ static void hvf_accel_class_init(ObjectClass *oc, const void *data) > ac->init_machine = hvf_accel_init; > ac->allowed = &hvf_allowed; > ac->gdbstub_supported_sstep_flags = hvf_gdbstub_sstep_flags; > + > + hvf_arch_accel_class_init(oc); > } > > static const TypeInfo hvf_accel_type = { > diff --git a/include/system/hvf.h b/include/system/hvf.h > index d3dcf088..3c4c3b89 100644 > --- a/include/system/hvf.h > +++ b/include/system/hvf.h > @@ -36,4 +36,19 @@ typedef struct HVFState HVFState; > DECLARE_INSTANCE_CHECKER(HVFState, HVF_STATE, > TYPE_HVF_ACCEL) > > +#ifdef CONFIG_HVF_IS_POSSIBLE > +/* > + * Minimum alignment for hv_vm_map(). Returns the configured IPA granule > + * or host page size if not set. > + */ > +void hvf_set_map_granule(uint64_t size); > +uint64_t hvf_get_map_granule(void); > +#else > +static inline void hvf_set_map_granule(uint64_t size) {} > +static inline uint64_t hvf_get_map_granule(void) > +{ > + return qemu_real_host_page_size(); > +} > +#endif > + > #endif > diff --git a/include/system/hvf_int.h b/include/system/hvf_int.h > index 2621164c..9589b022 100644 > --- a/include/system/hvf_int.h > +++ b/include/system/hvf_int.h > @@ -38,6 +38,7 @@ struct HVFState { > > hvf_vcpu_caps *hvf_caps; > uint64_t vtimer_offset; > + uint32_t ipa_granule; > QTAILQ_HEAD(, hvf_sw_breakpoint) hvf_sw_breakpoints; > }; > extern HVFState *hvf_state; > @@ -57,6 +58,7 @@ void assert_hvf_ok_impl(hv_return_t ret, const char *file, unsigned int line, > const char *hvf_return_string(hv_return_t ret); > int hvf_arch_init(void); > hv_return_t hvf_arch_vm_create(MachineState *ms, uint32_t pa_range); > +void hvf_arch_accel_class_init(ObjectClass *oc); > uint32_t hvf_arch_get_default_ipa_bit_size(void); > uint32_t hvf_arch_get_max_ipa_bit_size(void); > void hvf_kick_vcpu_thread(CPUState *cpu); > diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c > index 5fc8f6bb..1ba5bbf3 100644 > --- a/target/arm/hvf/hvf.c > +++ b/target/arm/hvf/hvf.c > @@ -12,6 +12,8 @@ > #include "qemu/osdep.h" > #include "qemu/error-report.h" > #include "qemu/log.h" > +#include "qemu/units.h" > +#include "qapi/error.h" > > #include "system/runstate.h" > #include "system/hvf.h" > @@ -1218,6 +1220,44 @@ void hvf_arch_vcpu_destroy(CPUState *cpu) > assert_hvf_ok(ret); > } > > +static char *hvf_get_ipa_granule(Object *obj, Error **errp) > +{ > + HVFState *s = HVF_STATE(obj); > + > + if (s->ipa_granule == 4 * KiB) { > + return g_strdup("4k"); > + } > + if (s->ipa_granule == 16 * KiB) { > + return g_strdup("16k"); > + } > + return g_strdup("auto"); > +} > + > +static void hvf_set_ipa_granule(Object *obj, const char *value, Error **errp) > +{ > + HVFState *s = HVF_STATE(obj); > + > + if (!strcmp(value, "auto")) { > + s->ipa_granule = 0; > + } else if (!strcmp(value, "4k")) { > + s->ipa_granule = 4 * KiB; > + } else if (!strcmp(value, "16k")) { > + s->ipa_granule = 16 * KiB; > + } else { > + error_setg(errp, "invalid ipa-granule: '%s' (use auto, 4k, 16k)", > + value); > + } There is a minor preference to use the glib functions here, g_strcmp0(). > +} > + > +void hvf_arch_accel_class_init(ObjectClass *oc) > +{ > + object_class_property_add_str(oc, "ipa-granule", > + hvf_get_ipa_granule, > + hvf_set_ipa_granule); > + object_class_property_set_description(oc, "ipa-granule", > + "IPA granule for HVF stage-2 translation (auto, 4k, 16k)"); > +} > + > hv_return_t hvf_arch_vm_create(MachineState *ms, uint32_t pa_range) > { > hv_return_t ret; > diff --git a/target/i386/hvf/hvf.c b/target/i386/hvf/hvf.c > index c0d028b1..565c79b3 100644 > --- a/target/i386/hvf/hvf.c > +++ b/target/i386/hvf/hvf.c > @@ -228,6 +228,10 @@ int hvf_arch_init(void) > return 0; > } > > +void hvf_arch_accel_class_init(ObjectClass *oc) > +{ > +} > + > /* 48-bit on all Intel Macs. Function currently unused. */ > uint32_t hvf_arch_get_default_ipa_bit_size(void) > { -- Alex Bennée Virtualisation Tech Lead @ Linaro ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v4 2/3] accel/hvf: introduce map granule abstraction and IPA property 2026-04-23 18:05 ` Alex Bennée @ 2026-04-23 23:44 ` Lucas Amaral 0 siblings, 0 replies; 8+ messages in thread From: Lucas Amaral @ 2026-04-23 23:44 UTC (permalink / raw) To: Alex Bennée Cc: Lucas Amaral, qemu-devel, qemu-arm, peter.maydell, agraf, mohamed Hi Alex, > There is a minor preference to use the glib functions here, g_strcmp0(). Will fix in v5, thanks. Lucas ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2026-04-24 7:39 UTC | newest] Thread overview: 8+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2026-03-17 17:48 [PATCH v4 0/3] hvf: map granule abstraction, configurable IPA, and MAP_FIXED alignment fix Lucas Amaral 2026-03-17 17:48 ` [PATCH v4 1/3] virtio-gpu: validate host page alignment for MAP_FIXED blobs Lucas Amaral 2026-03-17 17:48 ` [PATCH v4 2/3] accel/hvf: introduce map granule abstraction and IPA property Lucas Amaral 2026-03-17 17:48 ` [PATCH v4 3/3] target/arm/hvf: configure IPA granule on macOS 26 Lucas Amaral 2026-04-24 7:38 ` [PATCH v4 0/3] hvf: map granule abstraction, configurable IPA, and MAP_FIXED alignment fix Manos Pitsidianakis -- strict thread matches above, loose matches on Subject: below -- 2026-03-17 17:57 Lucas Amaral 2026-03-17 17:57 ` [PATCH v4 2/3] accel/hvf: introduce map granule abstraction and IPA property Lucas Amaral 2026-04-23 18:05 ` Alex Bennée 2026-04-23 23:44 ` Lucas Amaral
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