From a26ca6ad4c4aa4afcbfe4c46c33ad98859736245 Mon Sep 17 00:00:00 2001 From: Tina Zhang Date: Sun, 11 Feb 2018 14:59:19 +0800 Subject: [PATCH] drm/i915/gvt: Support BAR0 8-byte reads/writes GGTT is in BAR0 with 8 bytes aligned. With a qemu patch (commit: 38d49e8c1523d97d2191190d3f7b4ce7a0ab5aa3), VFIO can use 8-byte reads/ writes to access it. This patch is to support the 8-byte GGTT reads/writes. Ideally, we would like to support 8-byte reads/writes for the total BAR0. But it needs more work for handling 8-byte MMIO reads/writes. This patch can fix the issue caused by partial updating GGTT entry, during guest booting up. v3: - Use intel_vgpu_get_bar_gpa() stead. (Zhenyu) - Include all the GGTT checking logic in gtt_entry(). (Zhenyu) v2: - Limit to GGTT entry. (Zhenyu) Signed-off-by: Tina Zhang Signed-off-by: Zhenyu Wang --- drivers/gpu/drm/i915/gvt/kvmgt.c | 51 ++++++++++++++++++++++++++++++++++++++-- 1 file changed, 49 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c index 909499b73d03..021f722e2481 100644 --- a/drivers/gpu/drm/i915/gvt/kvmgt.c +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c @@ -733,6 +733,25 @@ static ssize_t intel_vgpu_rw(struct mdev_device *mdev, char *buf, return ret == 0 ? count : ret; } +static bool gtt_entry(struct mdev_device *mdev, loff_t *ppos) +{ + struct intel_vgpu *vgpu = mdev_get_drvdata(mdev); + unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos); + struct intel_gvt *gvt = vgpu->gvt; + int offset; + + /* Only allow MMIO GGTT entry access */ + if (index != PCI_BASE_ADDRESS_0) + return false; + + offset = (u64)(*ppos & VFIO_PCI_OFFSET_MASK) - + intel_vgpu_get_bar_gpa(vgpu, PCI_BASE_ADDRESS_0); + + return (offset >= gvt->device_info.gtt_start_offset && + offset < gvt->device_info.gtt_start_offset + gvt_ggtt_sz(gvt)) ? + true : false; +} + static ssize_t intel_vgpu_read(struct mdev_device *mdev, char __user *buf, size_t count, loff_t *ppos) { @@ -742,7 +761,21 @@ static ssize_t intel_vgpu_read(struct mdev_device *mdev, char __user *buf, while (count) { size_t filled; - if (count >= 4 && !(*ppos % 4)) { + /* Only support GGTT entry 8 bytes read */ + if (count >= 8 && !(*ppos % 8) && + gtt_entry(mdev, ppos)) { + u64 val; + + ret = intel_vgpu_rw(mdev, (char *)&val, sizeof(val), + ppos, false); + if (ret <= 0) + goto read_err; + + if (copy_to_user(buf, &val, sizeof(val))) + goto read_err; + + filled = 8; + } else if (count >= 4 && !(*ppos % 4)) { u32 val; ret = intel_vgpu_rw(mdev, (char *)&val, sizeof(val), @@ -802,7 +835,21 @@ static ssize_t intel_vgpu_write(struct mdev_device *mdev, while (count) { size_t filled; - if (count >= 4 && !(*ppos % 4)) { + /* Only support GGTT entry 8 bytes write */ + if (count >= 8 && !(*ppos % 8) && + gtt_entry(mdev, ppos)) { + u64 val; + + if (copy_from_user(&val, buf, sizeof(val))) + goto write_err; + + ret = intel_vgpu_rw(mdev, (char *)&val, sizeof(val), + ppos, true); + if (ret <= 0) + goto write_err; + + filled = 8; + } else if (count >= 4 && !(*ppos % 4)) { u32 val; if (copy_from_user(&val, buf, sizeof(val))) -- 2.11.0