Re: [PATCH V3 03/13] x86/HV: Add new hvcall guest address host visibility support
From: Dave Hansen <hidden>
Date: 2021-08-09 22:12:49
Also in:
linux-hyperv, linux-iommu, linux-scsi, lkml, netdev, xen-devel
On 8/9/21 10:56 AM, Tianyu Lan wrote:
From: Tianyu Lan <redacted> Add new hvcall guest address host visibility support to mark memory visible to host. Call it inside set_memory_decrypted /encrypted(). Add HYPERVISOR feature check in the hv_is_isolation_supported() to optimize in non-virtualization environment.
From an x86/mm perspective: Acked-by: Dave Hansen <redacted> A tiny nit:
quoted hunk ↗ jump to hunk
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index 0bb4d9ca7a55..b3683083208a 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c@@ -607,6 +607,12 @@ EXPORT_SYMBOL_GPL(hv_get_isolation_type); bool hv_is_isolation_supported(void) { + if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR)) + return 0; + + if (!hypervisor_is_type(X86_HYPER_MS_HYPERV)) + return 0; + return hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE; }
This might be worthwhile to move to a header. That ensures that hv_is_isolation_supported() use can avoid even a function call. But, I see this is used in modules and its use here is also in a slow path, so it's not a big deal