From mboxrd@z Thu Jan 1 00:00:00 1970 From: Feng Wu Subject: [v4 05/17] vt-d: VT-d Posted-Interrupts feature detection Date: Thu, 23 Jul 2015 19:35:41 +0800 Message-ID: <1437651353-5275-6-git-send-email-feng.wu@intel.com> References: <1437651353-5275-1-git-send-email-feng.wu@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1437651353-5275-1-git-send-email-feng.wu@intel.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org Cc: Yang Zhang , Kevin Tian , Feng Wu List-Id: xen-devel@lists.xenproject.org VT-d Posted-Interrupts is an enhancement to CPU side Posted-Interrupt. With VT-d Posted-Interrupts enabled, external interrupts from direct-assigned devices can be delivered to guests without VMM intervention when guest is running in non-root mode. CC: Yang Zhang CC: Kevin Tian Signed-off-by: Feng Wu --- v4: - Correct a logic error when setting iommu_intpost to 0 v3: - Remove the "if no intremap then no intpost" logic in intel_vtd_setup(), it is covered in the iommu_setup(). - Add "if no intremap then no intpost" logic in the end of init_vtd_hw() which is called by vtd_resume(). So the logic exists in the following three places: - parse_iommu_param() - iommu_setup() - init_vtd_hw() xen/drivers/passthrough/vtd/iommu.c | 18 ++++++++++++++++-- xen/drivers/passthrough/vtd/iommu.h | 1 + 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c index 9053a1f..4564a00 100644 --- a/xen/drivers/passthrough/vtd/iommu.c +++ b/xen/drivers/passthrough/vtd/iommu.c @@ -2071,6 +2071,9 @@ static int init_vtd_hw(void) disable_intremap(drhd->iommu); } + if ( !iommu_intremap ) + iommu_intpost = 0; + /* * Set root entries for each VT-d engine. After set root entry, * must globally invalidate context cache, and then globally @@ -2133,8 +2136,8 @@ int __init intel_vtd_setup(void) } /* We enable the following features only if they are supported by all VT-d - * engines: Snoop Control, DMA passthrough, Queued Invalidation and - * Interrupt Remapping. + * engines: Snoop Control, DMA passthrough, Queued Invalidation, Interrupt + * Remapping, and Posted Interrupt */ for_each_drhd_unit ( drhd ) { @@ -2162,6 +2165,15 @@ int __init intel_vtd_setup(void) if ( iommu_intremap && !ecap_intr_remap(iommu->ecap) ) iommu_intremap = 0; + /* + * We cannot use posted interrupt if X86_FEATURE_CX16 is + * not supported, since we count on this feature to + * atomically update 16-byte IRTE in posted format. + */ + if ( !iommu_intremap || !cap_intr_post(iommu->cap) || !cpu_has_cx16 ) + iommu_intpost = 0; + + if ( !vtd_ept_page_compatible(iommu) ) iommu_hap_pt_share = 0; @@ -2187,6 +2199,7 @@ int __init intel_vtd_setup(void) P(iommu_passthrough, "Dom0 DMA Passthrough"); P(iommu_qinval, "Queued Invalidation"); P(iommu_intremap, "Interrupt Remapping"); + P(iommu_intpost, "Posted Interrupt"); P(iommu_hap_pt_share, "Shared EPT tables"); #undef P @@ -2206,6 +2219,7 @@ int __init intel_vtd_setup(void) iommu_passthrough = 0; iommu_qinval = 0; iommu_intremap = 0; + iommu_intpost = 0; return ret; } diff --git a/xen/drivers/passthrough/vtd/iommu.h b/xen/drivers/passthrough/vtd/iommu.h index 80f8830..e807253 100644 --- a/xen/drivers/passthrough/vtd/iommu.h +++ b/xen/drivers/passthrough/vtd/iommu.h @@ -69,6 +69,7 @@ /* * Decoding Capability Register */ +#define cap_intr_post(c) (((c) >> 59) & 1) #define cap_read_drain(c) (((c) >> 55) & 1) #define cap_write_drain(c) (((c) >> 54) & 1) #define cap_max_amask_val(c) (((c) >> 48) & 0x3f) -- 2.1.0