[Intel-gfx] [PATCH v6 1/2] drm/i915/gvt: Save/restore HW status to support GVT suspend/resume
Zhenyu Wang
zhenyuw at linux.intel.com
Tue Oct 27 02:02:02 UTC 2020
On 2020.10.27 10:16:08 +0800, Colin Xu wrote:
>
> On 2020-10-27 09:49, Zhenyu Wang wrote:
> > On 2020.10.27 08:42:40 +0800, Colin Xu wrote:
> > > On 2020-10-26 17:19, Zhenyu Wang wrote:
> > > > On 2020.10.23 16:17:19 +0800, Colin Xu wrote:
> > > > > This patch save/restore necessary GVT info during i915 suspend/resume so
> > > > > that GVT enabled QEMU VM can continue running.
> > > > >
> > > > > Only GGTT and fence regs are saved/restored now. GVT will save GGTT
> > > > > entries on each host_entry update, restore the saved dirty entries
> > > > > and re-init fence regs in resume routine.
> > > > >
> > > > > V2:
> > > > > - Change kzalloc/kfree to vzalloc/vfree since the space allocated
> > > > > from kmalloc may not enough for all saved GGTT entries.
> > > > > - Keep gvt suspend/resume wrapper in intel_gvt.h/intel_gvt.c and
> > > > > move the actual implementation to gvt.h/gvt.c. (zhenyu)
> > > > > - Check gvt config on and active with intel_gvt_active(). (zhenyu)
> > > > >
> > > > > V3: (zhenyu)
> > > > > - Incorrect copy length. Should be num entries * entry size.
> > > > > - Use memcpy_toio()/memcpy_fromio() instead of memcpy for iomem.
> > > > > - Add F_PM_SAVE flags to indicate which MMIOs to save/restore for PM.
> > > > >
> > > > > V4:
> > > > > Rebase.
> > > > >
> > > > > V5:
> > > > > Fail intel_gvt_save_ggtt as -ENOMEM if fail to alloc memory to save
> > > > > ggtt. Free allocated ggtt_entries on failure.
> > > > >
> > > > > V6:
> > > > > Save host entry to per-vGPU gtt.ggtt_mm on each host_entry update.
> > > > >
> > > > > Signed-off-by: Hang Yuan <hang.yuan at linux.intel.com>
> > > > > Signed-off-by: Colin Xu <colin.xu at intel.com>
> > > > > ---
> > > > > drivers/gpu/drm/i915/gvt/gtt.c | 75 +++++++++++++++++++++++++++++
> > > > > drivers/gpu/drm/i915/gvt/gtt.h | 9 ++++
> > > > > drivers/gpu/drm/i915/gvt/gvt.c | 8 +++
> > > > > drivers/gpu/drm/i915/gvt/gvt.h | 3 ++
> > > > > drivers/gpu/drm/i915/gvt/handlers.c | 39 +++++++++++++--
> > > > > drivers/gpu/drm/i915/gvt/mmio.h | 3 ++
> > > > > drivers/gpu/drm/i915/intel_gvt.c | 15 ++++++
> > > > > drivers/gpu/drm/i915/intel_gvt.h | 5 ++
> > > > > 8 files changed, 154 insertions(+), 3 deletions(-)
> > > > >
> > > > > diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
> > > > > index a3a4305eda01..33385d640cb9 100644
> > > > > --- a/drivers/gpu/drm/i915/gvt/gtt.c
> > > > > +++ b/drivers/gpu/drm/i915/gvt/gtt.c
> > > > > @@ -636,9 +636,20 @@ static void ggtt_set_host_entry(struct intel_vgpu_mm *mm,
> > > > > struct intel_gvt_gtt_entry *entry, unsigned long index)
> > > > > {
> > > > > struct intel_gvt_gtt_pte_ops *pte_ops = mm->vgpu->gvt->gtt.pte_ops;
> > > > > + unsigned long offset = index;
> > > > > GEM_BUG_ON(mm->type != INTEL_GVT_MM_GGTT);
> > > > > + if (vgpu_gmadr_is_aperture(mm->vgpu, index << I915_GTT_PAGE_SHIFT)) {
> > > > > + offset -= (vgpu_aperture_gmadr_base(mm->vgpu) >> PAGE_SHIFT);
> > > > > + mm->ggtt_mm.host_aperture[offset].val64 = entry->val64;
> > > > > + mm->ggtt_mm.host_aperture[offset].dirty = true;
> > > > > + } else if (vgpu_gmadr_is_hidden(mm->vgpu, index << I915_GTT_PAGE_SHIFT)) {
> > > > > + offset -= (vgpu_hidden_gmadr_base(mm->vgpu) >> PAGE_SHIFT);
> > > > > + mm->ggtt_mm.host_hidden[offset].val64 = entry->val64;
> > > > > + mm->ggtt_mm.host_hidden[offset].dirty = true;
> > > > > + }
> > > > Looks 'dirty' flag is not needed at all, as what you need is to restore all present
> > > > entries, so can just check present bit of val64 for that.
> > > Strictly it's different. Host could update a page which isn't present but
> > > other PTE fields are still valid, this is "present". For dirty it's purpose
> > > is to record whether or not host has update this entry, regardless the page
> > > presence. If only check the present bit, there will be a case that previous
> > > PTE points to region that shouldn't be walked by the new PDE, but new
> > > PDE/PTE update only updates PDE w/ present, but PTE w/o present. That could
> > > leak information by new PDE + old PTE. Hypervisor should follow guest
> > > behavior to update all PDE/PTEs, and guest should make sure partial update
> > > won't leak information. If hypervisor doesn't follow guest page update,
> > > information could be leaked.
> > But this is only for GGTT which is just single level table right?
> >
> > > And actually, when vGPU created, all GGTT pages are updates so in practice,
> > > all entries are dirty. So from real practice, it's true that dirty check can
> > > be removed.
> > You mean guest would update all entries normally? That's ok which we just follow
> > guest's behavior. And we've also seen guest partial update of GGTT entry which
> > could be point for suspend/resume and we reset present bit at that time so can be
> > skipped in this case.
> Yes guest would update all. So should I check present again, or just
> save/restore all?
> >
I mean we could depend on present bit which not only represents guest state and
also could handle for partial update case as well.
> > > > > +
> > > > > pte_ops->set_entry(NULL, entry, index, false, 0, mm->vgpu);
> > > > > }
> > > > > @@ -1928,6 +1939,7 @@ static struct intel_vgpu_mm *intel_vgpu_create_ggtt_mm(struct intel_vgpu *vgpu)
> > > > > {
> > > > > struct intel_vgpu_mm *mm;
> > > > > unsigned long nr_entries;
> > > > > + u64 size;
> > > > > mm = vgpu_alloc_mm(vgpu);
> > > > > if (!mm)
> > > > > @@ -1944,6 +1956,25 @@ static struct intel_vgpu_mm *intel_vgpu_create_ggtt_mm(struct intel_vgpu *vgpu)
> > > > > return ERR_PTR(-ENOMEM);
> > > > > }
> > > > > + size = (vgpu_aperture_sz(vgpu) >> PAGE_SHIFT) *
> > > > > + sizeof(struct intel_vgpu_host_ggtt);
> > > > > + mm->ggtt_mm.host_aperture = vzalloc(size);
> > > > I think normally just write required size calculation in alloc parameter
> > > > instead of in extra variable.
> > > Only for trim line length within 80 otherwise align to parentheses doesn't
> > > look clean. Since kernel has 80 columns as the 'strong preferred limit', if
> > > it's OK I'll put it into same line then no extra variable is required.
> > No, that strong word is deprecated. ;)
> It makes the things easier.
> >
> > > > > + if (!mm->ggtt_mm.host_aperture) {
> > > > > + vfree(mm->ggtt_mm.virtual_ggtt);
> > > > > + vgpu_free_mm(mm);
> > > > > + return ERR_PTR(-ENOMEM);
> > > > > + }
> > > > > +
> > > > > + size = (vgpu_hidden_sz(vgpu) >> PAGE_SHIFT) *
> > > > > + sizeof(struct intel_vgpu_host_ggtt);
> > > > > + mm->ggtt_mm.host_hidden = vzalloc(size);
> > > > > + if (!mm->ggtt_mm.host_hidden) {
> > > > > + vfree(mm->ggtt_mm.host_aperture);
> > > > > + vfree(mm->ggtt_mm.virtual_ggtt);
> > > > > + vgpu_free_mm(mm);
> > > > > + return ERR_PTR(-ENOMEM);
> > > > > + }
> > > > > +
> > > > > return mm;
> > > > > }
> > > > > @@ -1971,6 +2002,8 @@ void _intel_vgpu_mm_release(struct kref *mm_ref)
> > > > > invalidate_ppgtt_mm(mm);
> > > > > } else {
> > > > > vfree(mm->ggtt_mm.virtual_ggtt);
> > > > > + vfree(mm->ggtt_mm.host_aperture);
> > > > > + vfree(mm->ggtt_mm.host_hidden);
> > > > > }
> > > > > vgpu_free_mm(mm);
> > > > > @@ -2852,3 +2885,45 @@ void intel_vgpu_reset_gtt(struct intel_vgpu *vgpu)
> > > > > intel_vgpu_destroy_all_ppgtt_mm(vgpu);
> > > > > intel_vgpu_reset_ggtt(vgpu, true);
> > > > > }
> > > > > +
> > > > > +/**
> > > > > + * intel_gvt_restore_ggtt - restore all vGPU's ggtt entries
> > > > > + * @gvt: intel gvt device
> > > > > + *
> > > > > + * This function is called at driver resume stage to restore
> > > > > + * GGTT entries of every vGPU.
> > > > > + *
> > > > > + */
> > > > > +void intel_gvt_restore_ggtt(struct intel_gvt *gvt)
> > > > > +{
> > > > > + struct intel_vgpu *vgpu;
> > > > > + struct intel_vgpu_mm *mm;
> > > > > + struct intel_vgpu_host_ggtt *host_ggtt;
> > > > > + int id;
> > > > > + u32 idx, num_low, num_hi, offset;
> > > > > +
> > > > > + /* Restore dirty host ggtt for all vGPUs */
> > > > > + idr_for_each_entry(&(gvt)->vgpu_idr, vgpu, id) {
> > > > > + mm = vgpu->gtt.ggtt_mm;
> > > > > +
> > > > > + num_low = vgpu_aperture_sz(vgpu) >> PAGE_SHIFT;
> > > > > + offset = vgpu_aperture_gmadr_base(vgpu) >> PAGE_SHIFT;
> > > > > + for (idx = 0; idx < num_low; idx++) {
> > > > > + host_ggtt = &mm->ggtt_mm.host_aperture[idx];
> > > > > + if (host_ggtt->dirty) {
> > > > > + write_pte64(vgpu->gvt->gt->ggtt,
> > > > > + offset + idx, host_ggtt->val64);
> > > > > + }
> > > > > + }
> > > > > +
> > > > > + num_hi = vgpu_hidden_sz(vgpu) >> PAGE_SHIFT;
> > > > > + offset = vgpu_hidden_gmadr_base(vgpu) >> PAGE_SHIFT;
> > > > > + for (idx = 0; idx < num_hi; idx++) {
> > > > > + host_ggtt = &mm->ggtt_mm.host_hidden[idx];
> > > > > + if (host_ggtt->dirty) {
> > > > > + write_pte64(vgpu->gvt->gt->ggtt,
> > > > > + offset + idx, host_ggtt->val64);
> > > > > + }
> > > > > + }
> > > > > + }
> > > > > +}
> > > > > diff --git a/drivers/gpu/drm/i915/gvt/gtt.h b/drivers/gpu/drm/i915/gvt/gtt.h
> > > > > index 52d0d88abd86..7ec333a2ead5 100644
> > > > > --- a/drivers/gpu/drm/i915/gvt/gtt.h
> > > > > +++ b/drivers/gpu/drm/i915/gvt/gtt.h
> > > > > @@ -139,6 +139,11 @@ struct intel_gvt_partial_pte {
> > > > > struct list_head list;
> > > > > };
> > > > > +struct intel_vgpu_host_ggtt {
> > > > > + u64 val64;
> > > > > + bool dirty;
> > > > > +};
> > > > > +
> > > > > struct intel_vgpu_mm {
> > > > > enum intel_gvt_mm_type type;
> > > > > struct intel_vgpu *vgpu;
> > > > > @@ -164,6 +169,9 @@ struct intel_vgpu_mm {
> > > > > } ppgtt_mm;
> > > > > struct {
> > > > > void *virtual_ggtt;
> > > > > + /* Save/restore for PM */
> > > > > + struct intel_vgpu_host_ggtt *host_aperture;
> > > > > + struct intel_vgpu_host_ggtt *host_hidden;
> > > > > struct list_head partial_pte_list;
> > > > > } ggtt_mm;
> > > > > };
> > > > > @@ -280,5 +288,6 @@ int intel_vgpu_emulate_ggtt_mmio_write(struct intel_vgpu *vgpu,
> > > > > unsigned int off, void *p_data, unsigned int bytes);
> > > > > void intel_vgpu_destroy_all_ppgtt_mm(struct intel_vgpu *vgpu);
> > > > > +void intel_gvt_restore_ggtt(struct intel_gvt *gvt);
> > > > > #endif /* _GVT_GTT_H_ */
> > > > > diff --git a/drivers/gpu/drm/i915/gvt/gvt.c b/drivers/gpu/drm/i915/gvt/gvt.c
> > > > > index c7c561237883..d0e9c43b031b 100644
> > > > > --- a/drivers/gpu/drm/i915/gvt/gvt.c
> > > > > +++ b/drivers/gpu/drm/i915/gvt/gvt.c
> > > > > @@ -405,6 +405,14 @@ int intel_gvt_init_device(struct drm_i915_private *i915)
> > > > > return ret;
> > > > > }
> > > > > +int
> > > > > +intel_gvt_pm_resume(struct intel_gvt *gvt)
> > > > > +{
> > > > > + intel_gvt_restore_regs(gvt);
> > > > > + intel_gvt_restore_ggtt(gvt);
> > > > > + return 0;
> > > > Please split restore_regs part which seems to be separate.
> > > Split intel_gvt_restore_regs() further to fence regs and normal tracked
> > > mmios with F_PM_SAVE?
> > yep, those for regs restore handling.
> >
> > Thanks
> >
> > > > > +}
> > > > > +
> > > > > int
> > > > > intel_gvt_register_hypervisor(struct intel_gvt_mpt *m)
> > > > > {
> > > > > diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
> > > > > index a81cf0f01e78..b3d6355dd797 100644
> > > > > --- a/drivers/gpu/drm/i915/gvt/gvt.h
> > > > > +++ b/drivers/gpu/drm/i915/gvt/gvt.h
> > > > > @@ -255,6 +255,8 @@ struct intel_gvt_mmio {
> > > > > #define F_CMD_ACCESS (1 << 3)
> > > > > /* This reg has been accessed by a VM */
> > > > > #define F_ACCESSED (1 << 4)
> > > > > +/* This reg requires save & restore during host PM suspend/resume */
> > > > > +#define F_PM_SAVE (1 << 5)
> > > > > /* This reg could be accessed by unaligned address */
> > > > > #define F_UNALIGN (1 << 6)
> > > > > /* This reg is in GVT's mmio save-restor list and in hardware
> > > > > @@ -685,6 +687,7 @@ void intel_gvt_debugfs_remove_vgpu(struct intel_vgpu *vgpu);
> > > > > void intel_gvt_debugfs_init(struct intel_gvt *gvt);
> > > > > void intel_gvt_debugfs_clean(struct intel_gvt *gvt);
> > > > > +int intel_gvt_pm_resume(struct intel_gvt *gvt);
> > > > > #include "trace.h"
> > > > > #include "mpt.h"
> > > > > diff --git a/drivers/gpu/drm/i915/gvt/handlers.c b/drivers/gpu/drm/i915/gvt/handlers.c
> > > > > index 89353b97589a..1f2432d7df34 100644
> > > > > --- a/drivers/gpu/drm/i915/gvt/handlers.c
> > > > > +++ b/drivers/gpu/drm/i915/gvt/handlers.c
> > > > > @@ -3120,9 +3120,10 @@ static int init_skl_mmio_info(struct intel_gvt *gvt)
> > > > > MMIO_DFH(TRVATTL3PTRDW(2), D_SKL_PLUS, F_CMD_ACCESS, NULL, NULL);
> > > > > MMIO_DFH(TRVATTL3PTRDW(3), D_SKL_PLUS, F_CMD_ACCESS, NULL, NULL);
> > > > > MMIO_DFH(TRVADR, D_SKL_PLUS, F_CMD_ACCESS, NULL, NULL);
> > > > > - MMIO_DFH(TRTTE, D_SKL_PLUS, F_CMD_ACCESS,
> > > > > - NULL, gen9_trtte_write);
> > > > > - MMIO_DH(_MMIO(0x4dfc), D_SKL_PLUS, NULL, gen9_trtt_chicken_write);
> > > > > + MMIO_DFH(TRTTE, D_SKL_PLUS, F_CMD_ACCESS | F_PM_SAVE,
> > > > > + NULL, gen9_trtte_write);
> > > > > + MMIO_DFH(_MMIO(0x4dfc), D_SKL_PLUS, F_PM_SAVE,
> > > > > + NULL, gen9_trtt_chicken_write);
> > > > > MMIO_D(_MMIO(0x46430), D_SKL_PLUS);
> > > > > @@ -3661,3 +3662,35 @@ int intel_vgpu_mmio_reg_rw(struct intel_vgpu *vgpu, unsigned int offset,
> > > > > intel_vgpu_default_mmio_read(vgpu, offset, pdata, bytes) :
> > > > > intel_vgpu_default_mmio_write(vgpu, offset, pdata, bytes);
> > > > > }
> > > > > +
> > > > > +static inline int mmio_pm_restore_handler(struct intel_gvt *gvt,
> > > > > + u32 offset, void *data)
> > > > > +{
> > > > > + struct intel_vgpu *vgpu = data;
> > > > > + struct drm_i915_private *dev_priv = gvt->gt->i915;
> > > > > +
> > > > > + if (gvt->mmio.mmio_attribute[offset >> 2] & F_PM_SAVE)
> > > > > + I915_WRITE(_MMIO(offset), vgpu_vreg(vgpu, offset));
> > > > > +
> > > > > + return 0;
> > > > > +}
> > > > > +
> > > > > +void intel_gvt_restore_regs(struct intel_gvt *gvt)
> > > > > +{
> > > > > + struct intel_vgpu *vgpu;
> > > > > + int i, id;
> > > > > + u64 val;
> > > > > +
> > > > > + idr_for_each_entry(&(gvt)->vgpu_idr, vgpu, id) {
> > > > > + mmio_hw_access_pre(gvt->gt);
> > > > > + for (i = 0; i < vgpu_fence_sz(vgpu); i++) {
> > > > > + val = vgpu_vreg64(vgpu, fence_num_to_offset(i));
> > > > > + intel_vgpu_write_fence(vgpu, i, val);
> > > > > + }
> > > > > +
> > > > > + intel_gvt_for_each_tracked_mmio(gvt,
> > > > > + mmio_pm_restore_handler, vgpu);
> > > > > +
> > > > > + mmio_hw_access_post(gvt->gt);
> > > > > + }
> > > > > +}
> > > > > diff --git a/drivers/gpu/drm/i915/gvt/mmio.h b/drivers/gpu/drm/i915/gvt/mmio.h
> > > > > index cc4812648bf4..999d9dda0614 100644
> > > > > --- a/drivers/gpu/drm/i915/gvt/mmio.h
> > > > > +++ b/drivers/gpu/drm/i915/gvt/mmio.h
> > > > > @@ -104,4 +104,7 @@ int intel_vgpu_mmio_reg_rw(struct intel_vgpu *vgpu, unsigned int offset,
> > > > > int intel_vgpu_mask_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
> > > > > void *p_data, unsigned int bytes);
> > > > > +
> > > > > +void intel_gvt_restore_regs(struct intel_gvt *gvt);
> > > > > +
> > > > > #endif
> > > > > diff --git a/drivers/gpu/drm/i915/intel_gvt.c b/drivers/gpu/drm/i915/intel_gvt.c
> > > > > index 99fe8aef1c67..4e70c1a9ef2e 100644
> > > > > --- a/drivers/gpu/drm/i915/intel_gvt.c
> > > > > +++ b/drivers/gpu/drm/i915/intel_gvt.c
> > > > > @@ -24,6 +24,7 @@
> > > > > #include "i915_drv.h"
> > > > > #include "i915_vgpu.h"
> > > > > #include "intel_gvt.h"
> > > > > +#include "gvt/gvt.h"
> > > > > /**
> > > > > * DOC: Intel GVT-g host support
> > > > > @@ -147,3 +148,17 @@ void intel_gvt_driver_remove(struct drm_i915_private *dev_priv)
> > > > > intel_gvt_clean_device(dev_priv);
> > > > > }
> > > > > +
> > > > > +/**
> > > > > + * intel_gvt_resume - GVT resume routine wapper
> > > > > + *
> > > > > + * @dev_priv: drm i915 private *
> > > > > + *
> > > > > + * This function is called at the i915 driver resume stage to restore required
> > > > > + * HW status for GVT so that vGPU can continue running after resumed.
> > > > > + */
> > > > > +void intel_gvt_resume(struct drm_i915_private *dev_priv)
> > > > > +{
> > > > > + if (intel_gvt_active(dev_priv))
> > > > > + intel_gvt_pm_resume(dev_priv->gvt);
> > > > > +}
> > > > > diff --git a/drivers/gpu/drm/i915/intel_gvt.h b/drivers/gpu/drm/i915/intel_gvt.h
> > > > > index 502fad8a8652..d7d3fb6186fd 100644
> > > > > --- a/drivers/gpu/drm/i915/intel_gvt.h
> > > > > +++ b/drivers/gpu/drm/i915/intel_gvt.h
> > > > > @@ -33,6 +33,7 @@ int intel_gvt_init_device(struct drm_i915_private *dev_priv);
> > > > > void intel_gvt_clean_device(struct drm_i915_private *dev_priv);
> > > > > int intel_gvt_init_host(void);
> > > > > void intel_gvt_sanitize_options(struct drm_i915_private *dev_priv);
> > > > > +void intel_gvt_resume(struct drm_i915_private *dev_priv);
> > > > > #else
> > > > > static inline int intel_gvt_init(struct drm_i915_private *dev_priv)
> > > > > {
> > > > > @@ -46,6 +47,10 @@ static inline void intel_gvt_driver_remove(struct drm_i915_private *dev_priv)
> > > > > static inline void intel_gvt_sanitize_options(struct drm_i915_private *dev_priv)
> > > > > {
> > > > > }
> > > > > +
> > > > > +static inline void intel_gvt_resume(struct drm_i915_private *dev_priv)
> > > > > +{
> > > > > +}
> > > > > #endif
> > > > > #endif /* _INTEL_GVT_H_ */
> > > > > --
> > > > > 2.29.0
> > > > >
> > > > > _______________________________________________
> > > > > intel-gvt-dev mailing list
> > > > > intel-gvt-dev at lists.freedesktop.org
> > > > > https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev
> > > --
> > > Best Regards,
> > > Colin Xu
> > >
> --
> Best Regards,
> Colin Xu
>
--
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