From 68f2f2bc163d4427b04f0fb6421f091f948175fe Mon Sep 17 00:00:00 2001 From: Dexuan Cui Date: Thu, 24 Aug 2023 01:07:05 -0700 Subject: Drivers: hv: vmbus: Support fully enlightened TDX guests Add Hyper-V specific code so that a fully enlightened TDX guest (i.e. without the paravisor) can run on Hyper-V: Don't use hv_vp_assist_page. Use GHCI instead. Don't try to use the unsupported HV_REGISTER_CRASH_CTL. Don't trust (use) Hyper-V's TLB-flushing hypercalls. Don't use lazy EOI. Share the SynIC Event/Message pages with the hypervisor. Don't use the Hyper-V TSC page for now, because non-trivial work is required to share the page with the hypervisor. Reviewed-by: Michael Kelley Signed-off-by: Dexuan Cui Signed-off-by: Wei Liu Link: https://lore.kernel.org/r/20230824080712.30327-4-decui@microsoft.com --- arch/x86/hyperv/hv_init.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'arch/x86/hyperv/hv_init.c') diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index 255e02ec467e..c1c1b4e1502f 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -80,7 +80,7 @@ static int hyperv_init_ghcb(void) static int hv_cpu_init(unsigned int cpu) { union hv_vp_assist_msr_contents msr = { 0 }; - struct hv_vp_assist_page **hvp = &hv_vp_assist_page[cpu]; + struct hv_vp_assist_page **hvp; int ret; ret = hv_common_cpu_init(cpu); @@ -90,6 +90,7 @@ static int hv_cpu_init(unsigned int cpu) if (!hv_vp_assist_page) return 0; + hvp = &hv_vp_assist_page[cpu]; if (hv_root_partition) { /* * For root partition we get the hypervisor provided VP assist @@ -442,11 +443,21 @@ void __init hyperv_init(void) if (hv_common_init()) return; - hv_vp_assist_page = kcalloc(num_possible_cpus(), - sizeof(*hv_vp_assist_page), GFP_KERNEL); + /* + * The VP assist page is useless to a TDX guest: the only use we + * would have for it is lazy EOI, which can not be used with TDX. + */ + if (hv_isolation_type_tdx()) + hv_vp_assist_page = NULL; + else + hv_vp_assist_page = kcalloc(num_possible_cpus(), + sizeof(*hv_vp_assist_page), + GFP_KERNEL); if (!hv_vp_assist_page) { ms_hyperv.hints &= ~HV_X64_ENLIGHTENED_VMCS_RECOMMENDED; - goto common_free; + + if (!hv_isolation_type_tdx()) + goto common_free; } if (hv_isolation_type_snp()) { -- cgit