Kai Huang e56d28df2f x86/virt/tdx: Configure global KeyID on all packages ... After the list of TDMRs and the global KeyID are configured to the TDX module, the kernel needs to configure the key of the global KeyID on all packages using TDH.SYS.KEY.CONFIG. This SEAMCALL cannot run parallel on different cpus. Loop all online cpus and use smp_call_on_cpu() to call this SEAMCALL on the first cpu of each package. To keep things simple, this implementation takes no affirmative steps to online cpus to make sure there's at least one cpu for each package. The callers (aka. KVM) can ensure success by ensuring sufficient CPUs are online for this to succeed. Intel hardware doesn't guarantee cache coherency across different KeyIDs. The PAMTs are transitioning from being used by the kernel mapping (KeyId 0) to the TDX module's "global KeyID" mapping. This means that the kernel must flush any dirty KeyID-0 PAMT cachelines before the TDX module uses the global KeyID to access the PAMTs. Otherwise, if those dirty cachelines were written back, they would corrupt the TDX module's metadata. Aside: This corruption would be detected by the memory integrity hardware on the next read of the memory with the global KeyID. The result would likely be fatal to the system but would not impact TDX security. Following the TDX module specification, flush cache before configuring the global KeyID on all packages. Given the PAMT size can be large (~1/256th of system RAM), just use WBINVD on all CPUs to flush. If TDH.SYS.KEY.CONFIG fails, the TDX module may already have "converted" some memory for TDX module use. Convert the memory back so that it can be safely used by the kernel again. Note that this is slower than it should be because of the "partial write machine check" erratum which affects TDX-capable hardware. Also refactor and introduce a new helper: tdmr_do_pamt_func(). This takes a TDMR and runs a function on its PAMT. It looks a _bit_ odd to pass a function pointer around like this, but its use is pretty narrow and it does eliminate what would otherwise be some copying and pasting. [ dhansen: * munge changelog as usual * remove weird (*pamd_func)() syntax ] Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Isaku Yamahata <isaku.yamahata@intel.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Yuan Yao <yuan.yao@intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lore.kernel.org/all/20231208170740.53979-14-dave.hansen%40intel.com		2023-12-08 09:12:43 -08:00
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vmx	x86/virt/tdx: Configure global KeyID on all packages	2023-12-08 09:12:43 -08:00
Makefile	x86/virt/tdx: Wire up basic SEAMCALL functions	2023-09-12 16:30:27 -07:00